PRSS50 and neoplasm: Previously, we have demonstrated that TSP50 promoted cell proliferation and tumor formation through activation of NF-κB signaling pathway.22 To determine whether NF-κB activation was also necessary for TSP50-induced cell migration and invasion, a dominant-negative IκB mutant (IκB-SR) was transfected into control and TSP50-expressing CHO cells to block NF-κB activation as described previously,22 and the expression of IκB-SR and its effects on TSP50-induced p65 nuclear translocation was further determined (Figure 4a).