MTT assays showed that ectopic expression of PRSS3-V1 or PRSS3-V3 significantly inhibited HCC cell proliferation in contrast to notably enhancing the effect of ectopic PRSS3-V2 expression or nonfunctional PRSS3-V4 on HCC cell proliferation compared to the vector controls (Figure 4B). The gene discussed is PRSS3; the disease is hepatocellular carcinoma.