The disclosure relates to fusion proteins, methods of making fusion proteins, and methods of using fusion proteins, wherein the fusion proteins comprise a functional single-domain antibody (sdAb) or a functional variant thereof and a cytosine deaminase (CD) protein or a functional variant thereof, optionally connected via a peptide linker. The fusion proteins of the disclosure also have CD activity. The disclosure also relates to pharmaceutical compositions or formulations comprising such fusion proteins and pharmaceutically acceptable excipients, as well as medical uses of these fusion proteins.本發明涉及融合蛋白、製備融合蛋白的方法以及使用融合蛋白的方法，其中所述融合蛋白包含：單域抗體(sdAb)或其功能性變異體、和胞嘧啶脫氨酶(CD)蛋白或其功能性變異體，二者可選地經連接胜肽連接。本發明的融合蛋白還具有CD活性。本發明還涉及包含所述融合蛋白和藥學可接受的賦形劑的藥物組合物或製劑、以及這些融合蛋白的醫藥用途。
