A recombinant KLK1 (rKLK1) is allowed to be used 48 h after the onset of stroke, with a dose of 0.15 U/d, intravenously injected once a day, which can effectively improve blood flow.[42] Here we believe that to treat IBD patients and prevent chronic enteritis from turning into colorectal cancer, intravenous injection in the abdomen is a better method. This evidence concerns the gene KLK1 and colorectal cancer.