Notably, although expanded clonotypes were detectable in all TIL populations, they were more prominent among TIM-3+CXCR6+ cells (clusters 3–8) (Extended Data Fig. 6a–c), a result consistent with the notion that these differentiated TIL populations may arise locally through the proliferative expansion of a few tumour-specific TCF1+ TILs. The gene discussed is CXCR6; the disease is neoplasm.