Time-course expression profiles of two illustrative genes. Log-ratio of expression between two treatment groups for a) a gene without differential expression, and b) an illustrative differentially expressed gene. I is an indicator of differential expression. δ represents the log-fold change at the four time points.
Aryee et al. BMC Bioinformatics 2009 10:409 doi:10.1186/1471-2105-10-409