The complement proteins C3a and C5a, whose expression is elevated in different tumors such as lung adenocarcinoma or ovarian carcinoma, participate in the formation of new tumor blood vessels, which induce the expression of VEGF and platelet-derived growth factor subunit A (PDGFA), which might cause pulmonary TMA [43,44]. The gene discussed is PDGFA; the disease is lung adenocarcinoma.