THRSP and obesity due to melanocortin 4 receptor deficiency: We identified the TR/RXR pathway as one of the major canonical signalling pathways associated with fetal weight, including AKT3, FASN, LDLR, NCOA2, PPARGC1A, SREBF2 and THRSP. Thyroid hormone-responsive protein (THRSP) is involved in lipogenic processes and is associated with obesity [47] and differential intramuscular fat in cattle [48].