PSMB9 and melanoma: Inhibition of HDAC using romidepsin (a class I HDACi) in a melanoma mouse model increased the expression of genes related to MHC I antigen processing and presentation, including transporter 1, ATP binding cassette subfamily B member (TAP1), proteasome 20S subunit beta 9 (LMP2), and β-2-microglobulin (B2M), and improved the cytotoxic activity of CD8+ T cells151.