SLC9A4 and obesity due to melanocortin 4 receptor deficiency: Consequently, stratified analysis based on the comorbidity of obesity suggested potential heterogeneous effects from 3 of the 5 genes, i.e., with α = 7.14E−03, the associations of IKZF4 and IGSF5 are only seen in obese asthma; and the associations of RSPH3 and SLC9A4 are only seen in non-obese asthma.