CLDN4 and ovarian carcinoma: For example, claudin-4 is associated with developing therapy resistance independently (2), as are LAT1 (62) and SLC1A5.(63) Additionally, a key phenotype during ovarian cancer development is ascites formation, which is a hallmark of ovarian cancer malignancy and is closely related to the availability of metabolites for tumor cells (64–67), which can also negatively modulate immune cells (68).