PTH and Hypercalcemia: Other mechanisms involved in the genesis of hypercalcemia may be the production of interleukins and prostaglandins (such as E2), as seen in chronic myeloid leukemia [13], an ectopic activity of 1-α-hydroxylase leading to the formation of 1,25 dihydroxycholecalciferol and ectopic production of parathyroid hormone (PTH) [6].