In adult male Wistar rats, diabetes was induced by streptozotocin, while orally supplemented thymoquinone (35 mg kg−1 day−1) to the experimental subjects exhibited improvement in the glucose–insulin homeostasis‐related parameters, lipid profile parameters, integrity of pancreatic islets, and hepato‐renal functional and histomorphological statuses and enhanced the upregulated survivin, insulin‐producing β cells, endothelial cluster of differentiation 31, vascular endothelial growth factor, total glutathione, interleukin‐10 (IL‐10), and superoxide dismutase. This evidence concerns the gene INS and diabetes mellitus.