Real-time RT-PCR analysis of gene expression before, during and after cardiac rejection. The gene expression levels of CXCL9 (A), CXCL10 (B) and NPPA (C) in endomyocardial biopsies was determined in eight subjects using real-time RT-PCR. The different time-points in the histopathological sequence (before, during and after rejection) are indicated. Gene expression levels were relative to the reference gene peptidylprolyl isomerase A (PPIA). The results are presented as mean ± SEM. *: p < 0.05 (ANOVA).