PTHLH and neoplasm: In particular, PTHrP (1–34), released among the tumor-derived factors, was proven to stimulate thermogenic gene expression, specifically upregulating UCP1 and DIO2, the latter coding for type 2 iodothyronine deiodinase, a selenoenzyme which increases during cold stress only in brown adipose tissue, ultimately resulting in the onset of hypermetabolism [14].