The I-TASSER Suite is a stand-alone software package designed for protein structure and function prediction. It addresses the challenge of assigning structures and functions to proteins, which remains a significant issue in the postgenomic era. The suite includes four main steps: threading template identification, iterative structure assembly simulation, model selection and refinement, and structure-based function annotation. The I-TASSER Suite has been extensively tested in community-wide blind experiments, such as CASP10 and CAMEO, demonstrating its effectiveness in predicting protein structures and functions. Key features include six in-house threading algorithms, a local quality estimation method (ResQ), and EC and GO prediction algorithms. The suite is expected to facilitate large-scale applications in the biomedical community.The I-TASSER Suite is a stand-alone software package designed for protein structure and function prediction. It addresses the challenge of assigning structures and functions to proteins, which remains a significant issue in the postgenomic era. The suite includes four main steps: threading template identification, iterative structure assembly simulation, model selection and refinement, and structure-based function annotation. The I-TASSER Suite has been extensively tested in community-wide blind experiments, such as CASP10 and CAMEO, demonstrating its effectiveness in predicting protein structures and functions. Key features include six in-house threading algorithms, a local quality estimation method (ResQ), and EC and GO prediction algorithms. The suite is expected to facilitate large-scale applications in the biomedical community.