PCR amplification of FOXL2 and TERT promoter hotspot loci was performed using the AmpliTaq Gold 360 Master Mix kit (Life Technologies, ThermoFisher Scientific) using previously described primers [22 (link),23 (link)]. PCR fragments were cleaned using ExoSAP It (ThermoFisher Scientific) and Sanger sequenced as previously described [22 (link)].