Metformin treatment (5 mM) reportedly suppressed the cisplatin-induced extracellular signal-regulated kinase (ERK)-dependent upregulation of RAD51 by decreasing the levels of phosphorylated ERK1/2, decreasing the stability of the RAD51 protein, and inducing the 26S proteasome-dependent degradation of RAD51 in Hs578T and MDA-MB-231 triple-negative breast cancer (TNBC) cells [120]. This evidence concerns the gene RAD51 and triple-negative breast carcinoma.