Since recent studies reported the involvement of Cysltr1 in the spontaneous development of colorectal cancer and in the colitis-associated colon cancer model [30, 31], molecular target drugs for the first extracellular loop of CysLTR1 may exert therapeutic effects not only for asthma and rhinitis, but also for colon cancer. The gene discussed is CYSLTR1; the disease is colorectal cancer.