This study aimed at finding the effects of bavachinin, candidone, and tephrosin, as chemosensitizer, against ER-positive (estrogen receptor-positive) and PR-positive (progesterone receptor-positive) mitoxantrone (MX) resistant type of breast cancer cell line, MCF-7/MX, and the classical MDR cell line of gastric carcinoma resistant to daunorubicin, EPG 85.257 RDB cells. Here, ESR1 is linked to breast carcinoma.