G6PD and breast cancer: Pentose phosphate pathway (PPP) is a major glucose metabolism pathway, which is fundamental in cancer growth and metastasis.19 To determine the expression of PPP in breast cancer cells, G6PD and TKT, the key enzymes of PPP were detected in MCF‐7 and MDA‐MB‐231 breast cancer cells as well as MCF‐10A control cells.