For years, oncologists have confronted an incomplete victory in immunotherapy: drugs like pembrolizumab (Keytruda) and nivolumab (Opdivo) that unleash the immune system's T cells against cancer have transformed treatment for melanoma, lung cancer, and others — but a significant proportion of patients either never respond or stop responding after initial success. The reason has remained frustratingly unclear, pointing to some unknown internal mechanism that allows cancers to evade even a stimulated immune system.
A landmark study published in Nature on June 9, 2026 by Dr. André Veillette and colleagues at the Université de Montréal and the Montreal Clinical Research Institute may have found it. The researchers identified SLAMF6 — Signaling Lymphocytic Activation Molecule 6 — as a previously undercharacterized molecular receptor on the surface of T cells that functions as an internal, self-activating brake on the immune system's cancer-killing activity.
