Here we propose ITGA9 as a key player in the metastatic spreading of these tumours and introduce a new anti-metastatic peptide (inspired by a key domain frequently found in the ADAM family of proteins with the aim of inhibiting ITGA9 activity), with very promising preclinical evidence on preventing the establishment of metastasis, which may have potential applicability in a broad spectrum of tumour types. Here, ITGA9 is linked to neoplasm.