HDAC4 and cancer: The top pathways were (1) antigen presentation (FDR = 2.03E-05), which included HLA-A, HLA-B, HLA-C, HLA-DMB, HLA-DOB, HLA-DQB2, HLA-G, and PSMB5; (2) PD-1/PD-L1 cancer immunotherapy (FDR = 4.13E-04); (3) the xenobiotic metabolism AHR signaling pathway, which included genes for smoking (AHRR), alcohol metabolism (ALDH16A1) and histone modification (HDAC4); and (4) crosstalk between dendritic cells and natural killer cells (FDR = 3.75E-03), which included genes for immunity (HLA family) and inflammation (TNF).