METTL14 and obesity due to melanocortin 4 receptor deficiency: Notably, E3 ligase STUB1 induces ubiquitination and degradation of METTL14.[18] RPN11 induces deubiquitylation and upregulation of METTL3.[19] It is likely that ubiquitin E3 ligases and deubiquinating enzymes may act upstream to regulate METTL3 and METTL14 activities in obesity.