We studied the activity landscape of these peptides through two approaches that are frequently used with small organic compounds: Structure-Activity Similarity (SAS) map and the Structure-Activity Landscape Index (SALI). Both approaches are explained hereunder. A (SAS) map is a low-dimension graph for analyzing the structure-activity relationships (SAR) of the compound dataset. SAS maps are one of the early approaches to studying activity landscapes and rapidly identifying activity cliffs. Activity cliffs are pairs of compounds with high structure similarity but significantly different biological activity .