GJB2 knockdown GBM cells showed reduced expression of RAC small GTPases (RAC1-3) and the CDC42 effector CDC42SE2 that are involved in TNTs (Hanna et al, 2017; Zhang et al, 2020a), while no expression changes were found for previously identified TMT-regulating genes (Jung et al, 2017; Osswald et al, 2015), suggesting that GJB2 function may be specific to TNTs. The gene discussed is CDC42SE2; the disease is glioblastoma.