Previous in vitro studies showed that Pyk2 kinase activity along with paxillin activation contributes to NK cytotoxic efficiency [234,235,236,237] and inhibition of Pyk2 activity decreased NK trans-endothelial migration [69], indicating that Pyk2 and paxillin signalling could potentially mediate NK cell extravasation and tumour infiltration limiting tumour progression. This evidence concerns the gene PTK2B and neoplasm.