Broad grouping of the biological function investigation showed that gliclazide‐related genes are closely associated with cancer and its related signal pathway cascades, including (a) regulation of cancer cell proliferation via the tyrosine kinase inhibitor resistance pathway, (b) regulation of tumor growth, invasion, metastasis, and treatment resistance via the HIF‐1 signaling pathway, and (c) regulation of cancer signaling cascades via the PI3K–Akt pathway. The gene discussed is PIK3CA; the disease is cancer.