An early study by Laneve et al. (2007) showed that miR-9 was downregulated in 50% of primary neuroblastoma samples, and follow-up experiments demonstrated that miR-9 could act together with miR-125a and miR-125b to suppress cell proliferation by targeting a truncated isoform of the neurotrophin receptor tropomyosin-related kinase C (trkC) (Figure 1D). Here, NTRK3 is linked to neuroblastoma.