Histological examination of the distal colon was performed on paraffin-embedded sections by hematoxylin-eosin (HE) staining. The inflammatory damage score was determined as previously described[29 (link)] and was the sum of inflammation infiltrations, depth of lesions, destruction of crypt, and width of lesions. Immunohistochemistry for SHIP-1 was performed using the peroxidase-conjugated avidin-biotin method. Deparaffinized and rehydrated sections were incubated with rabbit polyclonal anti-SHIP-1 (1:300, Santa Cruz, CA, United States) followed by biotinylated secondary antibody (Mai Bio, Shanghai, China). Positive staining was indicated by gray and brown particles. Ten visual fields (× 400 magnification) were chosen randomly in each section for evaluation of stained cells. The final score was the product of the number of stained cells and staining intensities. Detailed counting methods are listed in Supplementary Table 1.