CLDN18 and cancer: Sorting the PSI values of CLDN18 revealed that the distribution of cancer types in samples with higher PSI values of CLDN18.2 was more diverse, but the distribution of cancer types in samples with higher PSI values of CLDN18.1 was more concentrated and included breast invasive carcinoma (BRCA), kidney renal clear cell carcinoma (KIRC), KIRP, LUAD, LUSC, and sarcoma (SARC) (Figure 2C).