Exosomes isolated from colorectal cancer contained high levels of CRNDE-h, which it delivered into CD4+ T cells in co-culture, thus increasing the percentage of Th17 and upregulating RORγt expression and IL-17 promoter activity. CRNDE-h binds to the PPXY motif of RORγt and inhibits its ubiquitination and degradation by disrupting its interaction with the E3 ubiquitin ligase Itch. Here, IL17A is linked to colorectal cancer.