A previously described (Liu et al., 2012; Hu et al., 2021) HFD and a low-dose STZ rat model was used in this study because rats treated for 12 weeks with HFD and one-time low-dose STZ injection (deemed T2DM rats in this study) closely mimic the clinical characteristics, such as reduced insulin sensitivity, dyslipidemia, and hyperglycemia, seen in T2DM patients (Zhang et al., 2008; Liu et al., 2012; Skovsø, 2014; Cui et al., 2018). This evidence concerns the gene INS and type 2 diabetes mellitus.