It is difficult to evaluate the role of endogenous calcitonin in metabolic diseases for a number of reasons: 1) only few studies have applied human calcitonin in humans, 2) there are currently no antagonists available which selectively target the monomeric calcitonin receptor (26), and 3) studies applying the more potent salmon calcitonin reveal effects attributable to amylin receptor activity as well (84). This evidence concerns the gene CALCA and metabolic disease.