In order to clarify whether ESM1 and ICAM‐1 expression in IH is regulated by miR‐181a1, miR‐181a1 mimic and miR‐181a1 mimic NC (non‐specific control RNA) were introduced into UV2 vascular endothelial cells, and cells were exposed to IH or normoxia. The gene discussed is ICAM1; the disease is isolated hemihyperplasia.