LAG3 and cancer: The analysis of a skin lesion biopsied at baseline revealed a scantly and heterogeneous T cell infiltrate poorly expressing the targeted immune checkpoints PD-1 and LAG3, the absence of PD-L1 expression in both cancer or stromal cells, and a MSS genotype, which are all hallmarks of tumors poorly responding to PD-1/PD-L1 blockade monotherapy, as reported in multiple previous clinical trials1.