CASP3 and breast cancer: Compared with FIH, this negative influence of PHD3 on proliferation was more serious in our study, and also confirmed in several other tumor types, including CRC, gastric cancer and breast cancer, which might involving HIF-1-dependent or independent pathway, such as IKKβ/NF-κB, the beta-catenin/T-cell factor, activation of caspase-3 and phosphorylation of focal adhesion kinase [42, 48, 49, 53].