In recent studies, gravity-driven platforms without an artificial membrane screened 3D PT structure by zonula occludens 1 (ZO-1) and acetylated α-tubulin immunostaining [69–71], cellular proliferation assays [69, 71–74] and epithelial barrier integrity assays [69, 73, 74] for drug-induced AKI. Here, TJP1 is linked to acute kidney injury.