In the post-HCT group we found significantly lower expression of AGTR2, FLJ32810, NR3C2 and TMEM133 genes, and significantly higher expression of BAT2D1, MOV10, PIK3CG and WNK1 genes compared with the obesity control group. The gene discussed is PIK3CG; the disease is obesity due to melanocortin 4 receptor deficiency.