Targeting Anchor residues in a fragment growing study ensures both efficiency and potency for the growing step. A Transient-category, is a binding site residue that has highly favorable interaction energy, however, might show moderate to low percentage of interaction (less accessible). This can be mainly because of the small volume of the space surrounding the chemical feature of the residue, which might increase or decrease upon performing molecular dynamics (e.g., opening or closing of cryptic pockets). Transient residues if targeted with a proper complimentary functional group can play a key role in increase binding affinity while positively influencing the ligand efficiency (LE; equation: 2).