MANF and obesity due to melanocortin 4 receptor deficiency: Elevated circulating MANF levels in prediabetic and T2DM patients (Wu et al., 2021; Fu et al., 2021)Plasma MANF levels reduced in MASLD patients (Sousa-Victor et al., 2019)Inconsistent results on circulating MANF levels in obesity (Tang et al., 2022)