PDCD1 and melanoma: Inhibition of autophagy-related protein phosphatidylinositol 3-kinase catalytic subunit type 3 (PIK3C3/VPS34) in melanoma with a genetic target or pharmacological inhibitors reprograms cold immune checkpoint blockade (ICB)-unresponsive tumors into inflamed immune-infiltrated tumors by recruiting NK and CD8+T cells into the tumor bed and as such improves the efficacy of anti-PD-1/PD-L1 immunotherapy (140, 141).