S1 Supporting Information for: Increasing C-Terminal Hydrophobicity Improves the Cell Permeability and Antiproliferative Activity of PACE4 Inhibitors against Prostate Cancer Cell Lines Vahid Dianati, † Anna Kwiatkowska, ‡ Frédéric Couture, ‡ Roxane Desjardins, ‡ Yves L. Dory † * and Robert Day ‡ * †Institut de Pharmacologie de Sherbrooke, Département de Chimie, Faculté des Sciences, Université de Sherbrooke, 3001, 12e Avenue Nord, Sherbrooke, Québec, J1H 5N4 (Canada) ‡Institut de Pharmacologie de Sherbrooke, Département de Chirurgie/Urologie, Université de Sherbrooke, 3001, 12e Avenue Nord, Sherbrooke, Québec, J1H 5N4 (Canada) Table of Contents: 1. The synthesis of compounds 3-21, 28 and 29 .…………………………………………………S2 2. Details of enzyme kinetic assays .…………………………………………………..……...…...S2 3. Cell toxicity experiments ..………………………………………………………....…………...S2 4. Analytical data of peptide inhibitors and their FITC-labeled analogues ..………..…..…….S3 5. 1 H NMR and 13 C NMR spectra …………………………………..…………..………...……..S11