Homology models, depicted in Figure , are crucial for investigating targets, as wetlab procedures have only been employed to a limited extent for examining less significant targets. As a result, other techniques, such as ab initio 3D structure prediction approaches besides TBM, have been enhanced over the past ten years. Another way to predict 3D structures is through ab initio investigations. Ab initio predicts the 3D structure of protein "from scratch" using physical principles. Examples of ab initio structure prediction programs are I-Tasser, Raptor-x, Robetta, and PSIPRED ( ).