PDRG1 and neoplasm: In order to determine if the STSFA scores correlate with the stage of the tumor, 203 genes from the model were grouped into stage groups (Additional file 12: Table S12 modified from Bueno et al. [4], and Additional file 13: Table S13) The expression level of eight genes (AIFM2, CDKN1B, KAT2B, MAP4K4, PDRG1, RRM2B, SLC2A4, ZMAT3) was considered significantly different between the stages 3 and 4 with p-value < 0.05 (Additional file 14: Figure S1).