To assess whether amplification and overexpression of CCNE1, PLEKHF1, POP4 and TSHZ3 would alter the response of breast cancer cells to common chemotherapeutic agents, we subjected cancer cells with or without 19q12 gene amplification to treatment with doxorubicin, cisplatin and paclitaxel upon silencing of these genes. The gene discussed is TSHZ3; the disease is cancer.