PTEN and sarcoma: Therefore, the aim of the present study is to quantitatively evaluate methylation status of CpGs within the PTEN promoter using MassARRAY Spectrometry and to determine whether aberrant PTEN promoter methylation occurs in STSs, whether methylation patterns affect expression levels of PTEN in sarcoma subtypes (SRTSs and NRTSs), and furthermore, whether any of these alterations has potential values serving as biomarkers of STSs.