CD8A and melanoma: According to the negative impact demonstrated by the seminal studies described above, a single-cell RNA sequencing (RNA-seq) study by Cron et al. [318] demonstrated that a single-nucleotide polymorphism (SNP) mutation, associated with a lower expression of PKCδ and implying a loss-of-function phenotype, results in a reduced B16.SIY melanoma growth, along with an increased intra-tumor infiltration of CD8+ T cells at the endpoint and better response to anti-PD-L1 therapy [318].