We tested amodiaquine against triple negative breast cancer (MDAMB231, and BT549); HER2 positive (SKBR3), and ER/PR positive/HER2 negative (MCF7) cell lines; to compare between SKBR3/BT549 vs. MDAMB231/MCF7 [8]. This evidence concerns the gene ESR1 and triple-negative breast carcinoma.