In the Footsteps of Lloyd J. Old: A Journey from Inspiration to Innovation in Cancer Immunology

"Immunology will be to the 21st century what microbiology was to the 20th."

 — Lloyd J. Old

When Lloyd J. Old spoke those words, he wasn’t just predicting the future; he was igniting it.

That vision crossed oceans and took root when renowned Brazilian microbiologist Luiz R. Travassos worked alongside Lloyd J. Old at the Sloan Kettering Institute. Until then, deeply immersed in the study of fungal biology, Prof. Travassos began to ask a new question: How does the immune system respond? That shift in perspective, sparked by Old’s prophetic insight, marked a turning point in his scientific journey. It was the beginning of his transition toward immunology, a path that would ultimately give rise to one of Latin America’s most influential immunology laboratories.

It was during my doctoral training under Professor Luiz R. Travassos that I was first introduced to the name Lloyd J. Old, a name that would go on to shape the trajectory of my entire scientific career. Professor Travassos, a pioneering microbiologist turned immunologist, once worked alongside Dr. Old, and carried forward his vision with remarkable dedication. I still remember the moment he introduced me to Dr. Old, not long before his passing in 2011 from cancer. That encounter left a lasting impression on me.

Lloyd J. Old was not only a founding father of cancer immunology but also a visionary who believed that the immune system held the key to unlocking new paradigms in cancer treatment. His groundbreaking work on BCG and its immune-modulatory effects laid the foundation for what would become modern-day cancer immunotherapy. Through his leadership at the Ludwig Institute for Cancer Research and as one of the founders of the Cancer Research Institute (CRI) in New York, Dr. Old cultivated a global network of scientists committed to the idea that cancer could, and should, be treated by mobilizing the immune system.

His influence extended far beyond the borders of the United States. Inspired by his friendship and intellectual collaboration with Dr. Old, my supervisor, Prof. Travassos, returned to Brazil and established the Experimental Oncology Unit (UNONEX), bringing with him the belief that melanoma could serve as a powerful model to study tumor immunobiology. This idea, revolutionary at the time, helped shape Brazil's early contributions to cancer immunology and inspired a generation of young scientists, including myself.

I was deeply moved by the narrative of Lloyd Old’s scientific journey: how he influenced a generation to migrate from traditional microbiology to a more integrative understanding of cancer and immunity. His work laid the groundwork for the breakthroughs that would follow—including those by Dr. James P. Allison and Dr. Tasuku Honjo, whose discoveries in immune checkpoint inhibition ultimately led to a Nobel Prize. While Dr. Old didn’t live to witness the full impact of the revolution he helped ignite, his fingerprints are all over the field of immunotherapy as we know it today.

From those early days in Brazil, stirred by these stories, I dedicated my career to understanding the complex interplay between cancer and the immune system. My focus evolved from mechanistic studies of immune resistance in solid tumors to the development of innovative therapeutic strategies, leveraging cutting-edge technologies such as single-cell analysis, spatial transcriptomics, and reverse-translational studies in human cohorts. These efforts aim to decode the molecular circuits that make tumors invisible or resistant to immune attack—and to develop antibodies and small molecules that can rewrite that story.

Along the way, I have forged international collaborations across the U.S., the U.K., and Europe. I have been fortunate to receive honors such as the Young Investigator Award from the Scandinavian Society for Immunology, publish impactful research in top-tier journals, and contribute to translational partnerships that bridge academia and industry.

My current work spans preclinical drug discovery, tumor immunobiology, and the clinical translation of novel biomarkers and therapeutic strategies. Whether through mentoring students in academic institutions or disseminating the latest clinical trial findings to the broader medical and scientific community, my mission remains clear: to educate, to innovate, and to contribute.

I believe that scientific discovery is most powerful when it connects people—scientists, clinicians, patients, and industry stakeholders—across disciplines and borders. It is a privilege to carry forward the legacy of mentors like Dr. Old and Prof. Travassos, as we continue to push the boundaries of what’s possible in the fight against cancer.

As Dr. Old once said, “Cancer immunology is a bridge between science and medicine.” I have taken that to heart, and my career stands as a testament to that bridge, built on hope, science, and the unwavering belief that the immune system can be our greatest ally against this disease.

Prof. Old analysing research results at MSKCC (2011). J Clin Invest. 2012;122(5):1588–1588. https://doi.org/10.1172/JCI64110.