To provide a protein specifically recognizing and/or breaking a specific cell, a DNA encoding the protein, a vector comprising the DNA, a transformed host cell comprising the vector and a pharmaceutical composition comprising the protein as an active ingredient.

The protein comprises amino acids composed of a specific amino acid sequence, amino acids in which one or more amino acids are lost, substituted, added or inserted and have cell-recognizing activity and/or cell- hindering activity in an active form. The DNA is composed of a nucleotide sequence of a sequence number 1 (refer to the specification). The DNA encodes a protein hybridizing with a nucleotide sequence which is complementary to the DNA composed of the sequence under stringent conditions and having cell- recognizing activity and/or cell-hindering activity in an active form.