KRT14 and neoplasm: Prior to the LC–MS/MS analyses and to achieve final concentration of 50 fmol/μL SIL standards in the sample as recommended in Clinical Proteomic Tumor Analysis Consortium (CPTAC) guidelines, the donors’ CIC, CIM, and MIM samples were spiked with SIL standards of the histone H3 K9[Poy]K14[Poy]-heavy and K9[Poy]K14[Ac]-heavy in the volumes that comprised 10% of the sample volume [25].