In our previous study, we found that stabilized dephosphorylated β-catenin translocates into the nucleus in SLFN5-siRNA-treated breast cancer MCF7 cell lines [16], so we primarily examined GSK-3β/β-catenin and its up- and downstream signaling molecules in A549 cells, observing that the GSK-3β/β-catenin pathway was regulated in response to SLFN5 in A549 cells, i.e., activated by SLFN5 knockdown, and was blocked in response to SLFN5 overexpression (Figure 4(a)). This evidence concerns the gene SLFN5 and breast carcinoma.