However, another study showed that the mismatch of R689C in the MSP protein does not affect its ability to bind to the SEMA domain of RON, but the serum level of MSP is regulated by SNP rs3197999 (MSPβR689C), which causes a decrease in serum MSP concentration, and this may be one of the mechanisms of IBD (70). Here, MST1 is linked to inflammatory bowel disease.