Titration response based on gene level analysis. To calculate the gene level expression values, the median expression value was calculated from probe sets common to both isoforms (the F and T probes). The fold change for each gene was determined between samples A and B, binned and assessed for correct titration of expression values among the four samples. Genes were filtered statistically and those with p values < 0.001 were analyzed. The left graph indicates genes which were more highly expressed in sample A than sample B (A > B), and the right graph displays genes which were more highly expressed in sample B versus sample A (B > A).