PIK3CD and melanoma: For example, a compound (D18) can be used to increase KDM5A level for PD-L1 upregulating through PI3K-AKT-S6K1 signalling, and to activate Toll-like receptors 7 and 8 (TLR7/8) signalling pathways40, thereby enhancing anti–PD-1 immunotherapy response in melanoma.