NFKB1 and obesity due to melanocortin 4 receptor deficiency: The signaling pathways involved include the classic nuclear transcription factor (NF-kB) or c-Jun N-terminal kinase pathways (Figure 1B) which act to up-regulate inflammation and suppress the activity of T regulatory cells (Tregs) (64), which were partly agreed with the obesity caused by Enterobacter cloacae B29.