PDC and hepatocellular carcinoma: Other than altered expression of PHD1 and PHD2 in NSCLC, pancreaticobiliary cancer, cervical carcinoma and CRC [27, 37–40], in current study, PHD1 and PHD2 remained unchanged in HCC compared with normal liver tissue, although PHD2 was considered as most abundant and important PHD isoform in setting the steady-state level of HIF-1α [41].