We found that both drugs inhibited PLK1 expression, but to our surprise, one downregulated mutant p53 expression in triple-negative breast cancer cells (MDA-MB-231) and the other upregulated wild-type p53 expression in estrogen receptor-positive breast cancer cells (MCF-7), both of which led to CDK4 downregulation. Here, ESR1 is linked to triple-negative breast carcinoma.