STRING analysis of metabolic and PI3K-Akt signalling pathways. STRING analysis, generating functional protein association networks, displays 64 proteins discovered to be upregulated in invasive melanoma compared with in situ melanoma, as listed in Table II. Highlighted in red are nine proteins that participate in metabolism (TPI1, PRDX6, ALDOA, ACSL1, MDH2, GAPDH, PGK1, PKM and FASN) and eight proteins that participate in the PI3K-Akt signalling pathway (YWHAE, YWHAQ, HSP90B1, YWHAB, YWHAZ, HSP90AB1, COL6A2 and COL6A1). PI3K, phosphoinositide 3-kinase; TPI1, triosephosphate isomerase; PRDX6, peroxiredoxin-6; ALDOA, fructose-bisphosphate aldolase A; ACSL1, acyl-CoA synthetase long-chain family member 1; MDH2, malate dehydrogenase, mitochondrial; GAPDH, glyceraldehyde-3-phosphate dehydrogenase; PGK1, phosphoglycerate kinase 1; PKM, pyruvate kinase isozymes M1/M2; FASN, fatty acid synthase; YWHAE, 14-3-3ε; YWHAQ, 14-3-3ζ; HSP90B1, endoplasmin; YWHAB, 14-3-3α/β; YWHAZ, 14-3-3ζ/δ; HSP90AB1, heat shock protein HSP 90-β; COL6A2, collagen α-2(VI) chain; COL6A1, collagen α-1(VI) chain.