ACTB and breast cancer: Heart lysates from control mice, mice inoculated with BT474 breast cancer cells or mice inoculated with BT474 cancer cells and treated with DOX/TRZ treatment were probed for tight junction-associated protein ZO-1, occludin, claudin, and JAM-A by Western blot with expression levels of each protein quantified relative to β-actin (Fig. 4c).