PART 1: Fragments as a Pre-Screen to Assess Target Drugability This is the first in a series of blogs discussing the concept of using fragment screening to assess target drugability (also termed ligandability in the literature). The idea of using a fragment pre-screen to assess the likelihood of identifying a compound for lead optimization is not a new one. Because simple fragments have a higher probability of binding to targets than more complicated ligands (Hann et al., 20