An in vitro experiment showed that metformin-induced triglyceride fatty acids (TGFA) accumulation in 2 cell lines: estrogen/progesterone receptor positive human breast cancer cell lines (MCF7) and estrogen/progesterone receptor negative cell lines (MDA-MB-468), which was not affected by siRNA-mediated AMPK silencing (Lord et al., 2020). This evidence concerns the gene PGR and breast cancer.