We found the expression of Gpr18 mRNA also was increased in the colon of mice in the T cell transfer model of colitis (Figure S4B), to an even greater extent than Gpr183. Moreover, GPR18 expression affects intraepithelial lymphocytes (IEL) subpopulations (15) and based on RNAseq data, Gpr18 mRNA is expressed by mouse T cells (ImmGen database). Here, GPR18 is linked to colitis.