INS and Insulin resistance: To determine whether XIAP activity is essential for the regulation of metabolic balance, glucose tolerance tests (GTT) and insulin tolerance tests (ITT) were used to measure hepatic lipid metabolism indicators in both HFD- and SCD-fed mice As indicated in Figure 3A, ItsiXIAP/HFD and ItsiRNA/HFD mice had higher levels of glucose tolerance and insulin resistance than did the SCD-fed control group.