Table 1.

Summary of clinical studies of Frizzled (FZD) receptors in hepatocellular carcinoma (HCC).

Frizzled Receptors	Expression Status in HCC	Proposed/Proven Functional Significance	Reference
3/6/7	Upregulation	—Deregulation of FZD3/6/7 appeared to be a common and an early event during hepatocarcinogenesis.	[8]
1/7	Upregulation	—Expression of FZD1/7 was associated with myofibroblast activation in HCC.	[53]
2	Upregulation	—FZD2 expression was correlated with poorly differentiated HCC and late stage HCC. —HCC patients with high FZD2 expression were associated with poor recurrence-free survival. —FZD2 conferred EMT and HCC aggressiveness through activation of Wnt signaling.	[58,59]
7	Upregulation	—Deregulation of FZD7 appeared to be an early event during hepatocarcinogenesis. —Upregulation of FZD7 was associated with nuclear accumulation of wild-type β-catenin and activation of Wnt/β-catenin pathway in HCC. —Wnt3 activated Wnt/β-catenin pathway through direct binding with FZD7 in HCC.	[45,60,61]