Actinin, alpha 4 (ACTN4), a nonmuscle cytoskeleton protein, has been frequently reported to be associated with cell motility and cancer metastasis. Honda et al. have suggested that cytoplasmic ACTN4 increases cell motility and is associated with a high metastatic potential and a poor prognosis of cancer based on their studies on multiple cancer cell lines. Since then, ACTN4 has been reported to be associated with the progression and metastasis of many types of cancer, including breast, colorectal, pancreatic, lung, brain, bladder, and ovarian cancers and salivary gland carcinoma.