IL21 and central nervous system cancer: Corroborating these finding, recent spatial profiling of human glioma-associated TLSs showed that Th17-like cells expressing markers of LTi functions represent up to 50% of all T cells forming the TLS [67], and adoptively transferred Th17-polarized cells promoted long-lasting B cell-mediated antitumor immunity, upon IL21 secretion and CD40L-dependent co-stimulation, in a preclinical model of melanoma [68].