PFKFB3 and breast cancer: For instance, under progestin stimulation, dual mechanisms operate to ensure glycolysis in breast cancer cells (increased expression and increased phosphorylation of PFKFB3).27 To protect cancer cells from harm from high ROS, HeLa cells and human leukemia U937 cells utilize two different modifications of PFKFB3 (S-glutathionylation and demethylation of PFKFB3).40,41 Desideri et al.44 suggested that decreased PFKFB3 entails loss of autophagy in HeLa cells, leading to increased resistance to nutrient deprivation.