HCAR1 and Cachexia: To nail down the role of adipose GPR81 in the pathogenesis of cachexia, we generated adipose tissue-specific GPR81 knockout mice (GPR81fl/flAdipoqcre) that had about 70% reduction of GPR81 expression at its protein and mRNA levels in adipocytes (Fig. 4d and Extended Data Fig. 7h).