Both adipocytes and adipose macrophages express CD1d and they have been reported to interact with NKT cells in adipose tissue and promote diet-induced obesity-associated inflammation (Huh et al., 2017, Satoh et al., 2016, Satoh et al., 2022, Zhang et al., 2018). This evidence concerns the gene CD1D and obesity due to melanocortin 4 receptor deficiency.