Enhanced activation of G6PD/PPP, which is crucial for retaining the increased level of GSH, has been found in tumor cells resistant to various anti-tumor drugs, including tumor cells resistant to cisplatin, paclitaxel, doxorubicin, lapatinib, tamoxifen, 5-fluorouracil (5-FU), and cytarabine, as reported in different studies [115,116,121,146]. Here, G6PD is linked to neoplasm.