GLI1 and cancer: At the cellular level, the fact that several components of this newly identified loop have been reported to drive GLI1 transcriptional activity independently of the VEGF-NRP2 pathway in cancer cells suggests the presence of signalling pathways that could overcome anti-NRP2 therapies by keeping an active GLI1 downstream of this receptor (Hui & Angers, 2011; Lauth & Toftgård, 2011; Perrot et al, 2013; Aberger et al, 2012; Ji et al, 2007; Mangelberger et al, 2012).