STAT1 and melanoma: To quantify the relationship between the nitrated STAT1 peptide and the native STAT1 peptide the measurement of the ratio of the concentration of [GTGnYIK] to the concentration of [GTGYIK] was plotted for the 9 normal donors, 8 melanoma patients and 8 pancreatic cancer patients (Fig. 7C, Supplemental Fig. 5).