Colorectal cancer (CRC) is the third most common form of malignancy and the second leading cause of cancer-related death worldwide.1 Patients with right-sided CRC have a worse prognosis than left-sided CRC and it has already been reported that they do not respond well to conventional chemotherapies.2 Chemotherapy drugs used to treat CRC primarily include oxaliplatin and cytotoxic drugs that inhibit the enzyme activity of thymidylate synthase 5-Fluorouracil. The gene discussed is TYMS; the disease is colorectal carcinoma.