Global Mouse mRNA and Protein Levels Comparison Figure 4. Isoform-specific analysis of peptide data. A) An example of differential regulation of isoforms detected in the LC-MS data. Top panel, comparison of similarity in expression variation of 20 peptides measured for Acox1. Grey plots illustrate the expression variation among inbred mice for 19 peptides which represent all four Acox1 isoforms. Red plot illustrated the expression profile of the peptide representing the isoforms skipping PLoS Genetics | www.plosgenetics.org 7 June 2011 | Volume 7 | Issue 6 | e1001393