Apelin signalling is known to drive formation of new blood vessels in both physiology and disease (Kälin et al., 2007; Yang et al., 2016; Helker et al., 2020; Berta et al., 2021), and it has recently been shown that apelin receptor knockdown or receptor inhibition with a peptide antagonist reduces vascularisation and angiogenesis in GBM (Mastrella et al., 2019). This evidence concerns the gene APLN and glioblastoma.