Table S1. Ten Most Highly Upregulated Immune-Related in the TME Post-G100 Treatment in Patients with MCC (for All Patients, Responders, and Non-Responders) All Patients (N = 10) Mean Expression Ratio** P- (Post/Pre-G100) Value Protein/Immune-related Gene Function(s) LTF 3.52 0.0078 Lactotransferrin IL1RN 3.46 0.0194 Interleukin 1 inhibitor; innate immunity COL3A1 3.20 0.0976 Collagen α-1(III) chain/platelet activation MME 2.97 0.0494 Membrane metalloendopeptidase/innate immunity FOS 2.82 0.0416 Fos proto-oncogene/AP-1 transcription factor subunit S100A7 2.73 0.0678 Calcium-binding protein A7 (psoriasin)/immunomodulation CD36 2.71 0.1154 Platelet glycoprotein 4 SPP1 2.54 0.1686 Osteopontin/macrophage and T-cell chemotaxis CXCL12 2.52 0.1153 Stromal cell-derived factor 1 (SDF1)/immune surveillance and inflammation EGR1 2.52 0.0060 Early growth response protein 1 (aka, Zif268 or NGFI-A) Clinical Responders (N = 4) Mean Expression Ratio Gene (Post/Pre-G100) Protein/Immune-related Gene Function(s) SPP1* 8.66 Osteopontin/macrophage and T-cell chemotaxis CXCL8/IL8 5.92 Neutrophil chemotactic factor; chemokine IL1RN* 5.83 Interleukin 1 inhibitor; innate immunity TREM2 5.38 TREM-2/activation of monocyte-derived dendritic cells COL3A1* 5.32 Collagen α-1(III) chain/platelet activation MSR1 4.51 Macrophage scavenger receptor 1/adhesion of macrophages FOS 3.80 Fos Proto-Oncogene/AP-1 Transcription Factor Subunit FN1 3.63 Fibronectin 1 Solute carrier family 11 member 1/host resistance to certain SLC11A1 1.71 pathogens S100A7 1.38 Calcium-binding protein A7 (psoriasin)/immunomodulation Clinical Non-Responders (N = 6) Mean Expression Ratio Gene (Post/Pre-G100) Protein/Immune-related Gene Function(s) LTF* 3.74 Lactotransferrin TPSAB1 3.72 α/β-1/protease in mast cells and ; innate immunity CTSG 3.71 G/neutrophil CXCL14 3.68 BRAK/monocyte and dendritic cell chemotaxis and activation SAA1 3.62 Serum amyloid A1/ inflammatory responses CMA1 3.59 Chymotryptic serine proteinase C3 3.33 Complement C3/complement pathway and innate immunity MS4A2 3.25 Membrane spanning 4-domains A2 LBP 3.13 Lipopolysaccharide binding brotein CXCL12* 3.13 Stromal cell-derived factor 1 (SDF1)/immune surveillance and inflammation * Also appears in the top 10 most highly-upregulated immune-related genes for all patients ** All expression ratios shown are presented as antilogarithms of the means of the log2 fold-change data (post/pre). P-values are based on log2 fold change post to pre-G100. Due to the small sample numbers, p- values are not provided for responder and non-responder groups.

5