Specifically, TILs in MF patients exhibit an exhausted phenotype, which is characterized by the upregulation of various co-inhibitory receptors such as PD-1 (program death 1, encoded by PDCD1) and TIM-3 (T cell immunoglobulin and mucin domain-containing protein 3, encoded by HAVCR2/TIM-3) [99]. The gene discussed is HAVCR2; the disease is mycosis fungoides.