As an important co-chaperone of HSP90, P23 binds stably with HSP90 in cancer cells to form a superchaperone complex 38 and can also bind with HSP90 in the absence of any client protein 38; in contrast, XRCC1 requires binding with HSP90 as a chaperone molecule to participate in DNA repair 40. Here, XRCC1 is linked to cancer.