KDM4A, B, C, and D’s expression is tightly regulated in non-neoplastic tissues but often deregulated in several neoplasias such as prostate, liver, bladder, colorectal, squamous cell carcinomas, acute myeloid leukemia, breast, lung and ovarian cancer (Guerra-Calderas et al., 2015, 2018; Lu et al., 2015; Lin et al., 2019; Chen et al., 2020; Wu et al., 2021). The gene discussed is KDM4A; the disease is ovarian carcinoma.