Mezheyeuski A, et al. - The expression patterns of claudin-2 in human colorectal cancer (CRC) samples were comprehensively scrutinized. Researchers also examined its association with clinical characteristics and therapeutic outcome. Based on the results, it was found that previously unreported stromal expression of claudin-2 in cancer-associated fibroblasts (CAFs) of human CRC was detected together with a prominent link between high claudin-2 expression in CAFs and shorter survival in 5-FU+oxaliplatin-treated metastatic CRC (mCRC) patients.