This graphic combines data corresponding to the genes analyzed by real-time PCR in all tested tissues. The Y-axis represents the total number of clones detected at a given amplification cycle range (X-axis). Genes that are considered "not expressed" on arrays (background tag < 0.9) are represented by red squares (327 clones) Expressed genes on arrays (background tag > 0.9) are represented by blue diamonds (399 clones).