Since ZO-1 and ZONAB are critical modulators determining the switching time for epithelial cells along proximal tubules changing from a proliferative (nuclear/cytoplasmic ZONAB) state to a differentiated (ZO-1-bound ZONAB) one [46], we monitored the high expression rate of ZO-1 and ZONAB in BC and observed a negative correlation between their expression, which means that ZO-1 and ZONAB interaction might be involved in BC development. The gene discussed is YBX3; the disease is breast cancer.