GJA1 and glioblastoma: Indeed, GBM cells are interconnected (between them) through tumor microtubes (TMs) that join single cells via gap junctions (GJs), mainly formed by Cx43, and form an intracellular pathway (Osswald et al. (2015) [268]) with important roles both in tumor progression and in resistance to cytotoxic therapies (Weil et al. (2017) [269]; Li et al. (2020) [270]).