“…For the remaining cases that were Sanger sequenced, paired normal DNA was not available, and thus we cannot ascertain the somatic origin of S1PR1 mutations in these cases. However, in-depth analyses were made to subtract all previously known somatic variants as described by Wu et al 17 Information on age, sex, stage, and survival status were collected from patients' records. Genomic DNA was extracted from peripheral blood, frozen tumor samples, or viability frozen cells using DNeasy Blood & Tissue Kit (Qiagen, Hilden, Germany) or GenElute Mammalian Genomic DNA Miniprep Kit (Sigma, Taufkirchen, Germany), following the manufacturers' instructions.…”