These data suggest that the lack of Irs2 in the MΦs led to an increase in the number of M1-type MΦs and the M1/M2 ratio, and a decrease in the number of M2a-subtype MΦs in the WAT, resulting in the aggravation of insulin resistance in the MIrs2KO mice under the HF diet condition. This evidence concerns the gene IRS2 and hydrops fetalis.