G6PD and cancer: While G6PD induction by 1,25(OH)2D3 is beneficial in pre-malignancy, and thus in chemoprevention, as demonstrated by Bao et al. [43], the induction of G6PD expression/activity by 1,25(OH)2D3 in cancer cells could possibly be pro-survival, since (i) G6PD is a putative oncogene that is overexpressed in many cancers [40], and (ii) due to the possible subsequent increase in the rate of the PPP, which could provide rapidly proliferating cells with precursors for anabolic processes [44].