CHEK1 and cancer: The top ten most frequent prognostic epifactor genes across the cancer types (Fig. 4b) were involved in chromatin remodeling (DPF1 and TOP2A) and in depositing and reading histone modifications including histone phosphorylation, methylation, and deubiquitination (AURKA, BUB1, CDK1, CHEK1, GSG2, MSH6, SMYD2, and USP49).