NFE2L2 and obesity due to melanocortin 4 receptor deficiency: Moreover, given that small heterodimer partner (Shp) represses Cyp7a1 expression [37], and Nrf2 induces Shp gene expression [38], a reasonable hypothesis could be that Nrf2 represses Cyp7a1 expression through Shp. This repression of Cyp7a1 expression is abrogated by Nrf2 deletion, leading to increased levels of Cyp7a1 in Nrf2-KO mice compared to WT, which may partially protect them from obesity [39].