PIK3R2 and melanoma: To identify targets regulated by miR-126-3p that could affect proliferation, invasiveness and response to dabrafenib of the drug-resistant cells, we focused our attention on ADAM9 (a disintegrin and a metalloproteinase domain 9), MMP7 (matrix metallopeptidase 7) and PIK3R2 (phosphoinositide-3-kinase regulatory subunit 2), three miR-126-3p target genes already validated in melanoma cells [26] and shown to be involved in melanoma invasiveness (ADAM9 and MMP7) [26] and acquired resistance to BRAFi (PIK3R2) [6].