PCNA and B-cell chronic lymphocytic leukemia: PCNA (proliferating cell nuclear antigen), which favors the recruitment of DNA polymerase to DNA strand breaks, DDB1 (damage-specific DNA binding protein), which recognizes UV-induced DNA lesions, and MC2, a substrate of ATM and ATR upon DNA damage, are reduced upon HSP90 inhibition by SNX-7081 in CLL [140].