While FOXA2 has been shown to control mRNA levels of PDX1, HNF1A, and HNF4A, mutations in HNF1A, HNF1B, HNF4A, and PDX1 are known to cause maturity-onset diabetes of the young (MODY) (Burgos et al, 2021). Here, HNF4A is linked to type 2 diabetes mellitus.