CLDN4 and breast cancer: The EMT-related genes were LRPPRC, AGR2, CLDN4, CRIP1, DSP, ELF3, JUP, KRT8, KRT18, KRT19, FAM102A, TACSTD2, EPCAM, PEBP1, PSMD8, RAN, SNRPC, SPTAN1, EZR, DDR1, MLPH, and WDR34. In which, gene SNRPC, upregulated in CTC clusters, is a metastatic novel biomarker in breast cancer.