We investigated whole transcriptome activity in MCF-7 cancer cells stimulated by HRG-beta and EGF at 18 time points (t = 0, 10, 15, 20, 30, 45, 60, 90[min], 2, 3, 4, 6, 8, 12, 24, 36, 48, tT = 72[h]), and considered the expression of all probes (N = 22035; Gene Expression Omnibus database ID: GSE13009; see Methods) assigned to each gene or open reading frame (ORF) in microarray data; we call such probes ‘mRNA expression’, which includes the expression of genes as well as the expression of variants of mRNA. The gene discussed is EGF; the disease is cancer.