GPER-knockout mice show visceral obesity, increased low-density lipoprotein cholesterol levels, insulin resistance, hyperglycaemia, reduced glucose tolerance, generalised inflammation, increased blood pressure, cardiovascular dysfunction, decreased skeletal development leading to reduced body growth, diminished serum insulin-like growth factor 1 levels, and impaired T cell production; however, in contrast to ERα-knockout mice, GPER-knockout mice display no reduction in fertility [19,20,22,23,24]. The gene discussed is GPER1; the disease is Insulin resistance.