TJP1 and breast cancer: ZO-1 protein expression was markedly decreased in BC cell lines (UM-UC-3: 0.63 ± 0.22, T24: 0.58 ± 0.24) over that of noncancer urothelial cell line sv-huc-1 (1.0 ± 0.33, P < 0.05, Figure 1(b)).