HIF1A and cancer: In addition to the driver mutation, alteration of tumor microenvironments was critical for cancer progression.6, 7 In these environments, HIF‐1α was known as a master regulator to adapt hypoxic condition.25 It is also well known that HIF‐1α was upregulated in many types of cancers.9, 10, 26 From these previous reports and our results, HIF‐1α in the hypoxic condition of tumor microenvironments would play a role as one of the major triggers of malignant transformation from AB to AC.