SOX2 and neoplasm: Similarly, Tseng et al., 2022 [58], found that recurrent cases of Ab showed much higher labeling indices of SOX2 than paired primary lesions, and proposed that recurrence of Ab is associated with the presence of SOX2-expressing stem cells, as some tumor nests might be remained when the tumor was not adequately removed, SOX2 expressing cells remaining in these nests might give rise to the recurrent disease.