OCLN and Alzheimer disease: Experimental studies indicate that calycosin may modulate the Toll-like receptor (TLR) 4/NF-κB signaling pathway, suppress the expression of TSLP and IL-33, and increase tight junction proteins such as ZO-1 and occludin in both human immortalized keratinocyte cell line (HaCaT) and mouse AD models (Tao et al., 2017).