The importance of HH–GLI signaling in tumour maintenance and stemness properties [24] has been also described in other CSC contexts, such as colon and lung cancer, in various ways for instance through a non-canonical signalling, involving NRP2 (Neuropilin 2) and MAP/ERK (Mitogen Activated Protein Kinase/Extracellular Signal-Regulated Kinase) signalling [25]. Here, NRP2 is linked to lung cancer.