HMOX1 and neoplasm: Moreover, HO-1 overexpression positively correlates to the thymidine phosphorylase (TP), a proangiogenic enzyme, overexpressed in different human tumors such as NSCLC, breast, and colorectal cancers [108,109] and contributes to higher microvessel density, metastasis, more advanced tumor stage, and poor prognosis [109].