ACTB and breast cancer: While examining the protein content of SEVs derived from three breast cancer cell lines (MCF-7, MDA-MB-231, and T47D), Dalla and colleagues (2020) [49] found that seven proteins were the most abundant (actin cytoplasmic 1, pyruvate kinase, glyceraldehyde-3-phosphate dehydrogenase, 60 kDa mitochondrial heat shock protein, mitochondrial ATP synthase alpha subunit, sodium/potassium transport ATPase beta-3 subunit, and voltage-dependent anion selective protein channel 2).