FCN2 and obesity due to melanocortin 4 receptor deficiency: To the best of our knowledge, there is no previous literature claiming a direct T2D (or prediabetes) association for the following 5 proteins: IL1RAP, IGFBP6, APOD, COMP, and FCN2, although a few sources suggest associations with weight, obesity, inflammation, or a role in adipose tissue (42–48).