Fig. 3

Spatially coordinated changes to phosphorylated ERK-MAPK components within human epidermis. a Human epidermis simultaneously labeled against phospho-Raf-1 (pS338; cyan), phospho-MEK-1/2 (pS218/pS222; magenta) and phospho-ERK-1/2 (pT183/pY185; yellow). Scale bar represents 10 μm, image data have undergone non-linear transformation to improve printed appearance. b The normalized abundance of cytoplasmic (solid lines) and nuclear (dashed lines) phospho- Raf-1, −MEK-1/2, and ERK-1/2 (colors as above) within interfollicular keratinocytes undergoing terminal differentiation in situ. The c Pearson’s correlation and d mutual information were calculated between all pairwise combinations of target variables using the spatially-conditioned abundance data (grey histograms; axes at left). The strength of these statistical associations was compared to a null distribution calculated from spatially-scrambled data (red probability density function [p.d.f]; axes at right), which was used to calculate two-sided (Pearson’s correlation) and one-sided (mutual information) 99 % confidence intervals (blue vertical lines). For details on the strength of individual relationships please refer to Additional file 6: Table S1