To examine the effect of EVs derived from SIPA1-expressing breast cancer cells on the infiltration of macrophages in vivo, we employed an animal model based on MDA-MB-231 orthotopic mice and treated mice with 231-EVs (n = 6), 231/si-EVs (n = 6), or PBS (n = 6) as control. The gene discussed is SIPA1; the disease is breast cancer.