The GST Mu 1 (GSTM1) rs1056806 [C/T], GST theta 1 (GSTT1) rs17856199 [A/C], GST Pi 1 (GSTP1) rs1695 [A/G], and microsomal GST3 (mGST3) rs2065942 [C/T] variants of this family can impair the GSTs catalytic activities and are studied in multiple diseases, including obesity and related comorbidities [16,27]. The gene discussed is GSTP1; the disease is obesity due to melanocortin 4 receptor deficiency.