As breast cancer subtypes, ER negative (p < 0.001), PgR negative (p < 0.001), HER2 positive (p = 0.002), and high Ki67 (p = 0.005) were significantly more likely to achieve pCR, so HER2BC (p < 0.001) and TNBC (p = 0.031) were significantly more likely to have pCR. The gene discussed is ESR1; the disease is breast cancer.