This disclosure relates to a chimeric antigen receptor for binding with a tumor specific target antigen. The chimeric antigen receptor comprises at least one antigen specific targeting region evolved from a parent protein or a fragment thereof and having a decrease in activity in the assay at the normal physiological condition compared to the activity in the assay under the aberrant condition. A method for producing the chimeric antigen receptor is also provided.本發明係關於一種用於與腫瘤特異性靶抗原結合之嵌合抗原受體。該嵌合抗原受體包含至少一個自親本蛋白質或其片段進化且相比於在異常條件下分析中之活性,在正常生理條件下分析中之活性降低的抗原特異性靶向區。亦提供一種用於產生該嵌合抗原受體之方法。