CHEK2 and acute myeloid leukemia: Different from AML, three proteins increased with age (CHEK2-pThr68, SSBP2, XPA) and ten showed no association with age (CHEK1, CHEK1-pSer345, CHEK2, MSH2, MSH6, RAD50, RPA32, TP53, WEE1 and XRCC1).