STAT3 and telomere syndrome: Our additional preliminary study reported that STAT3 inhibitor S3I-201 inhibited pSTAT3 in the majority of STS cell lines [22], with the IC50s on the three wild-type STS cell lines 778, 449B and HT1080 being 148.5, 95.5 and 14.5μM, respectively (sensitivity threshold for S3I-201: IC50≤100μM).