PSMB9 and cancer: Additionally, other PSM genes have been associated with cancer progression (e.g. PSMD9 (p27) and PSMD10 (p28)), increased radiation sensitivity in breast cancer (e.g. absence of p27), as well as, increased risk of colorectal cancer (e.g. PSMB8 and PSMB9) [3, 11, 26–29].