PTGER3 and obesity due to melanocortin 4 receptor deficiency: Although the LysM-Cre-based gene deletion was also detected in neutrophils (Orthgiess et al, 2016), neutrophils account for only <5% of the total infiltrated immune cells in WATs from patients with obesity and obese mice compared to nearly 50–70% macrophages (Emont et al, 2022; Massier et al, 2023; Vijay et al, 2020), indicating that the phenotype is mainly contributed by EP3-deficient macrophages.