We showed that TIM-3 mRNA expression in primary PBMNCs were significantly decreased in the proband and her family members than that of sporadic T cell lymphoma and healthy individuals with wild-type TIM-3, which is consistent with the mRNA expression of TIM-3 in the transgenic HEK293 cells, suggesting Tyr82Cys and Arg89Cys double mutation of TIM-3 is a loss-of -function mutation,and reduced TIM-3 expression may contribute to the pathogenesis of T cell lymphoma and immune imbalance of HLH. This evidence concerns the gene HAVCR2 and hemophagocytic syndrome.