Using iterClust (50), we defined nondiabetic enriched β cells with strong INS/MAFA activity but no metabolic inflexibility markers as “healthy β cells” (Hβ cells) and T2D enriched β cells with increased α cell and metabolic inflexibility markers as “metabolically inflexible β cells” (MIβ cells) (Figure 7A and ref. 48). The gene discussed is INS; the disease is type 2 diabetes mellitus.