Interestingly, 9 TS genes with S > 0 or S < 0 were found to be indeed significantly down-expressed in cancer at stage 1, while the other TS genes such as EXT1, KLK10, NBL1, RHOB, PTCH1 that were not found to be down-expressed in early cancer had S of zero, that is, these of being not differentially expressed between normal and cancer samples at stage 1 were not found to be correlated with other functional genes in expression in early cancer. The gene discussed is PTCH1; the disease is cancer.