CLDN4 and neoplasm: Higher mRNA levels of genes related to chemoresistance, that is, (TGM1) transglutaminase 1, heat shock proteins and metallothioneins, to cell–cell adhesion and also barrier molecules, that is, (PKP3) plakophilin 3, (PPL) periplakin, (CLDN4/7) claudin 4/7, and (FLG) filaggrin, were found in ascites spheroids versus tumor tissue as well.