S100A4 and obesity due to melanocortin 4 receptor deficiency: Other notable interactions include Protein S100-A13 (S10AD, S100A13 gene) and Protein S100-A4 (S10A4, S100A4 gene) of the S100 protein family, which exhibit various functions, including stress-induced release of growth factors and adipogenesis regulation, with potential implications for obesity and insulin resistance25–27.