In line with the Warburg effect, it has been shown that triple negative breast cancer (TNBC) and HER2 positive breast cancer possess higher levels of glycolytic activity than estrogen receptor positive (ER+) breast cancer cells (Choi et al., 2013; Pelicano et al., 2014; Lanning et al., 2017). The gene discussed is ESR1; the disease is breast cancer.