After 26–46 months of follow-up, we found that a high level of serum β2M had nearly three times the risk of recurrent AIS (HR 3.105, 95% CI, 1.579–6.103) by means of the Cox proportional hazard regression model, suggesting that β2M is a reliable predictive risk factor for recurrent AIS. The gene discussed is B2M; the disease is androgen insensitivity syndrome.