Relative expression of immune related genes in the 12 point timecourse of mammary development. Immune-related transcripts differentially expressed in the 12-point developmental time course were grouped into five categories that represent different immunological functions. The number of transcripts in each category is shown in brackets. Genelists of all transcripts assigned to these immunological categories are available online. (a) The frequency of transcripts in each expression profile cluster for each immunological category. Statistically significant associations, as determined by Onto-Express, are indicated with asterisks. Y axes indicate the percentage for each cluster. X axis indicates the combined expression profile clusters. (b) The mean expression profiles for all transcripts in each immunological category. Y axis indicates the mean normalized signal intensity, and the X axis indicates the 12 developmental time points (see Fig. 1).