CLDN4 and mastitis: The results showed that after BBR-CEH treatment, the mRNA expression of <i>TNF-α</i> (tumor necrosis factor-alpha), <i>IL-6</i> (interleukin-6), and <i>IL-1β</i> (interleukin-1 beta) was significantly decreased, the mRNA expression of <i>ZO-1</i> (zonula occludens-1), <i>Occludin</i>, and <i>Claudin-4</i> was significantly increased, and <i>Bax</i>/<i>Bcl-2</i> (Bcl-2-associated X protein/B-cell lymphoma 2) was significantly reduced (<i>p</i> < 0.01), indicating alleviation of mastitis by reducing inflammation, improving tight junctions, and inhibiting apoptosis.