GIP and type 2 diabetes mellitus: Tirzepatide (TRZD), the glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide/gastric inhibitory peptide (GIP) agonist, has recently gained interest as a promising injectable drug for the treatment of type 2 diabetes and was approved by the FDA after successful clinical trials (SURPASS 1/2/3/4 and 5, NCT03954834, NCT03987919, NCT03882970, NCT03730662, and NCT04039503).