When analyzed the percentage variability explained by the demographic and clinical features including age, weight, height, BMI, cumulative dose, radiation, cancer level, treatment type, other drugs, cancer relatives, marital state, diabetes, dyslipidemia, ER, PR, and Her 2 status against the echocardiography parameters six months after the completion of anthracycline chemotherapy, the highest variability was observed for the EF among the six echocardiography parameters. The gene discussed is ESR1; the disease is cancer.