ACTR2 and breast cancer: The increased expression of Arp2/3 complex subunits is evident in different cancers and correlates with poor prognosis, for example, the Arp2/3 subunit 5 (ARPC5) in head and neck cancer and lung squamous cell carcinoma, subunit 3 (ARPC3) and 4 (ARPC4) in pancreatic cancer, Arp2 and WAVE in breast cancer, and Arp2 and Arp3 in colorectal and gastric cancers.17