TGM2 and breast cancer: TG2 has been also evaluated as a promising breast cancer prognostic biomarker that sustains cell proliferation and glycolytic metabolism through the mitogen-activated protein kinase/extracellular signal-related protein kinase/lactate dehydrogenase (MEK/ERK/LDH) pathway or by inducing hypoxia-inducible factor 1-alpha (HIF-1α) via NF-κB [64].