Several of the proteins whose level changes early for some tumor types (glyceraldehyde-3-phosphate dehydrogenase (GAPDH), B4GalT1, death receptor 6 (DR6, also known as tumor necrosis factor receptor superfamily member 21 (TNFRSF21), sulfhydryl oxidase 1 (QSCN6), arginosuccinate lyase (ASL), DLD, tryptophanyl-tRNA synthetase (WRS), biotinidase (BTD) and NDPK are among the 15 shared biomarkers that indicate the presence of any of the four tumor types studied. Here, QSOX1 is linked to neoplasm.