DKK1 and obesity due to melanocortin 4 receptor deficiency: DKK1 is produced by numerous cells, including osteogenic cells, platelets, adipocytes, fibroblasts, and vascular cells.27, 55, 56, 57 As obesity is associated with an expansion of adipose tissue and adipocytes express DKK1, it may be envisaged that DKK1 produced from this cell type may play a major role.