In an attempt to address this issue, Li et al. (2022) asked: “Could it be because of some biological property of the insulin-secreting pancreatic β cells that makes them susceptible to the deleterious effects of heterozygous but not homozygous variants?” Interestingly, however, rather than giving an answer to this question, Li et al. proposed that autosomal recessive forms of MODY “are at least as common as the dominant ones, but have not been discovered yet”. This evidence concerns the gene INS and MODY.