For example, periostin, a secretory protein that plays a crucial role in angiogenesis and is highly expressed in 60% of HCC patients, through a positive feedback loop with TGFβ, can activate AP-2α to transcriptionally induce the expression of CD133, which promotes the stemness transformation of HCC cells [58]. The gene discussed is TGFB1; the disease is hepatocellular carcinoma.