Signaling axes for transcription factor activation consisting of molecular parameters. The multivariate data for signaling molecules and transcription factor activation were taken into a partial least square regression model (see text for details). Panel A shows observed versus predicted values for transcription factor activation under various knockdown conditions. The signaling axes for transcription factor activation were determined using our approach to classify signaling parameters on principle component axis according to correlation with TF activation (see text for detail). The overlapping set of signaling parameters are pictorially depicted in panel B in a 3-D plot consisting of PC1 for pp65 and PC2 for NFAT and p-c-Jun model. Response specific signaling parameter tracks are shown in Panel C where unique, common to two and common to all three cellular responses are depicted schematically.