Analysis of 27 STAD tumor samples and 27 healthy control samples (Figure 1(d)) showed that 9 genes (NOTCH1, NOTCH3, NOTCH4, DLL4, JAG1, JAG2, HES1, and HEY1) were significantly upregulated in STAD tumor samples compared with healthy control samples, whereas 2 genes' (NOTCH2 and DDL1) expression levels did not differ significantly. The gene discussed is HEY1; the disease is neoplasm.