The ribosome pathway in MCF-7 and ZR75-1 cells. (a) All 12 genes in this pathway were down-regulated (GenMAPP) in MCF-7. (b) In contrast, all the 9 genes were up-regulated in ZR75-1 cells. The only common gene (*) in the small subunit (40S) is RPS16, which was down-regulated (-23.7 fold) in MCF-7 and up-regulated (7.5 fold) in ZR75-1 cells. The up-regulated ribosomal genes in ZR75-1 indicate increased protein synthesis in these cells in contrast to MCF-7 cells (also refer to CS3, Figure 3b).