ESR1 and breast cancer: Our medium lacking 10 NEAAs (M1) also induced selective cytotoxicity against other types of human breast cancer cells: BT-474 (luminal B type [ER+; PR+; Her-2+]), T-47D (luminal A type [ER+; PR+; Her-2-]) and SK-BR-3 (HER-2 positive) (Table S3 and Figure S1).