CHEK1 and neoplasm: Furthermore, we detected the mRNA expression of cell cycle-promoting genes in tumor-bearing tissues, and found that DJ-1 KO decreased the expression of cell cycle-promoting genes (CCNA1, CCNE1, CDK2, RRM2, FOXM1, TVMS and CHK1) (Figures 6C-K), but the expression of p53 and p73 remained unchanged significantly (Figures 6L, M).