HMGA2 and gastric cancer: Similarly, a metastatic gastric cancer cell line, AZ-P7a cells selectively secrete let-7 family miRNAs, which are considered mainly as tumor suppressor genes targeting oncogenes such as RAS and high-mobility group A2 (HMGA2), into the extracellular environment via exosomes to maintain their tumorigenic and metastatic propensities [21].