Fragment growing is one of the most applied FBDD approaches. Simply it is the addition of functional groups on identified hit fragment to increase interaction and affinity with target protein. Growth of fragment hits to sub-micromolar lead compounds is a bottle neck in drug discovery pipelines. Efficient fragment growing strategies must be employed to transform a fragment hit typically obeying the rule-of-three (Ro3) into a lead-like compound with optimal physiochemical properties. Typically, with good oral bioavailability, often rule-of-five (Ro5) compliant and increased ligand efficiency and potency. The addition of moieties onto a hit fragment requires the determination of proper directionality which are defined as "Growth Vectors". These are synthetically amenable positions on the core-scaffold where functional groups or building blocks can be attached.