PKM and breast cancer: Recent studies have reported that high PKM2 expression is associated with an unfavorable prognosis in multiple human tumors including hepatocellular carcinoma (Lv et al., 2018), breast cancer (Yang et al., 2017) and osteosarcoma (Liu et al., 2016), etc. Nevertheless, over-expression of PKM2 in gastric cancer and pancreatic cancer were not correlated with poor prognosis (Zhu et al., 2017).