ESR1 and androgen insensitivity syndrome: We found that there were 48% of AIS patients with significantly decreased ESR1 expression of concave paraspinal muscle progenitor cells (convex/concave >1.5 folds), while patients with more asymmetrical ESR1 expression showed more hypoplastic paraspinal muscle and fatty infiltration on the concave side, and more severe scoliotic deformity.