PAK4 and malignant colon neoplasm: Overexpression of PAK4 has been detected in human colon cancer cell lines29 as well as in primary mouse colon tumors.30 PAK4 gene was also observed to be amplified in CRC patient samples.31 Moreover, PAK4 is essential for HCT-116 colon cancer cell proliferation in anchorage-independent culture.29 It has been recently reported that PAK4 expression is associated with colorectal cancer infiltration and metastasis.32 In consistent with the previous studies, our results revealed that PAK4 promoted colon cancer cell growth (Figure 1e).