Part I - SI-NET tumors High Resolution Isoelectric Focusing (HiRIEF) LC-MS and relative quantification by iTRAQ 8-plex was used to analyze 14 small intestinal neuroendocrine tumors (SI-NETs). The data was obtained from two separate TMT10plex sets and linked by a single internal pooled standard. The internal pooled standard was made by combining equal aliquots of the tryptic peptide mixtures from each of the 14 tissue samples. iTRAQ set1 was composed of 7 SI-NET samples, all from different individuals, and internal pooled standard labelled as follows: Channel 113 (sample Screen-1 with liver metastasis), Channel 114 (sample Screen-8 with liver metastasis), Channel 115 (sample Screen-3 with liver metastasis), Channel 116 (sample Screen-2 with liver metastasis), Channel 117 (sample Screen-5 no liver metastasis), Channel 118 (sample Screen-4 no liver metastasis), Channel 119 (sample Screen-10 no liver metastasis), Channel 121 (internal pooled standard). iTRAQ set2 was composed of 7 SI-NET samples, all from different individuals, and internal pooled standard labelled as follows: Channel 113 (sample Screen-7 with liver metastasis), Channel 114 (sample Screen-11 with liver metastasis), Channel 115 (sample Screen-13 with liver metastasis), Channel 116 (sample Screen-6 no liver metastasis), Channel 117 (sample Screen-12 no liver metastasis), Channel 118 (sample Screen-9 no liver metastasis), Channel 119 (sample Screen-14 no liver metastasis), Channel 121 (internal pooled standard). Part II - time course profiling in cell lines High Resolution Isoelectric Focusing (HiRIEF) LC-MS and relative quantification by TMT 10-plex was used to analyze cellular response to the neddylation inhibitor pevonedistat (MLN4924) at different timepoints in two SI-NET (small intestinal neuroendocrine tumors) cell lines. The data was obtained from two separate TMT 10-plex experiments. TMT set1 includes a time course experiment upon pevonedistat treatment of CNDT2 cells with harvests at 2h, 6h, 12h and 24h after treatment as well as of untreated control cells. Isobaric tag labelling of peptide samples with TMT10plex was used as follows. Biological duplicate controls (TMT channels 126, 127N), duplicate 2h (127C, 128N), duplicate 6h (128C, 129N), duplicate 12h (129C, 130N) and duplicate 24h (130C, 131) samples were employed. TMT set2 includes a time course experiment upon pevonedistat treatment of HC45 cells with harvests at 2h, 6h, 12h and 24h after treatment as well as of untreated control cells. Isobaric tag labelling of peptide samples with TMT10plex was used as follows. Biological duplicate controls (TMT channels 126, 127N), duplicate 2h (127C, 128N), duplicate 6h (128C, 129N), duplicate 12h (129C, 130N) and duplicate 24h (130C, 131) samples were employed.