AFPs have been found in various insects, fish, bacteria, fungi, and overwintering plants such as gymnosperms, ferns, monocotyledonous, angiosperms, etc. [4] [5] [6] [7] [8] [9] [10] [11] [12] . Relational analyses show that there is low sequence or structure similarity for an ice-binding domain, and lack of common features among different AFPs [7] [8] [9] [10] . One reason for this phenomenon is that ice can present many different surfaces with different arrangements of oxygen atoms [8] . So it is difficult to establish powerful prediction methods to identify AFPs. However, AFPs play important roles in different fields, such as freeze-resistant transgenic plants and animals, food technology, preservation of cell lines, organs and cryosurgery [13, 14] . How to discriminate AFPs from other proteins is important in understanding protein-ice interactions and creating new ice-binding domains in other proteins.