The results showed that CYS treatment significantly recovered ZO-1 protein expression (CIS group: 0.61 ± 0.13 (p value = 0.001 compared with the control group); 0.1 mM: 0.78 ± 0.12 (p value = 0.58 compared with CIS group); 0.2 mM: 0.75 ± 0.24 (p value = 0.75 compared with CIS group); 0.5 mM: 0.87 ± 0.23 (p value = 0.11 compared with CIS group); 1 mM: 0.95 ± 0.31 (p value = 0.017 compared with CIS group)) (Figure 6). The gene discussed is TJP1; the disease is in situ carcinoma.