Some in vitro studies have demonstrated the overexpression of CysLT1R in various cancer cells, including renal cell carcinoma [7,8], transitional cell carcinoma [7,9], prostate cancer [7,10], testicular cancer [7,11], and colon cancer [12], while montelukast induced the apoptosis of these cancer cells. The gene discussed is CYSLTR1; the disease is colonic neoplasm.