FFAR2 and cancer: There are two explanations for the specific mechanism: First, SCFAs may affect the neutrophil L-selectin shedding through GPR43.161 However, there are also experimental results that showed SCFA treatment can increase L-selectin expression and L-selectin mRNA levels on the surface of neutrophils,162 which may be related to the cancer-promoting effect caused by GPR43 deficiency.