CDK8 and fibrosarcoma: We then compared the relative levels of CDK8 and CDK19 between 293 and several other human cell lines (HeLa cervical carcinoma, HCT116 colon carcinoma, HT1080 fibrosarcoma, MV4-11 acute myeloid leukemia, HAP1 chronic myeloid leukemia), as well as 22Rv1 prostate cancer cell line, which represents the only type of cancer where CDK19 is known to be systematically upregulated (40–43).