PLS1 and cervical cancer: We conducted IHC staining to further validate differences in the protein expression of 11 specific genes, PRAME, HMGA2, SBK1, ETV4, MEX3A, PLS1, TM7SF2, PYCR1, SLC19A1, TTYH3, and NIPSNAP1, in HPV-negative cervical cancer in this study.