Fig. 1.

Phosphoprotein expression patterns in melanoma are highly heterogeneous. a The phosphorylation status of 11 kinases and kinase targets was determined in 24 unstimulated melanoma cell lines using xMAP ELISA. Circles summarise 264 quantifications. Circle sizes are proportional to the protein phosphorylation level analysed from n = 3 independently performed experiments. b A principal component analysis (PCA) was applied to the phosphoprotein data. Results are shown as a scree plot where bar graphs indicate the contribution of each principal component (PC) toward explaining the data variance. c The coefficients for all proteins in the first four PCs are shown as bar graphs. d Graphical illustration of the distribution of melanoma cell lines within the space defined by the first three PCs