The present invention deals with a ligand comprising each of the complementary-determining regions (CDRs) set forth in SEQ ID No. 1, SEQ ID No. 2, SEQ ID No. 3 SEQ ID No. 4, SEQ ID No. 5 and SEQ ID No. 6 or sequence having either number of substituted aminoacids within said sequences as indicated in the following, from 0 to 3 in CDR1(SEQ ID No. 1), from 0 to 2 in CDR2(SEQ ID No. 2), from 0 to 2 in CDR3(SEQ ID No. 3), from 0 to 1 in CDR4(SEQ ID No. 4), from 0 to 4 in CDR5(SEQ ID No. 5), from 0 to 2 in CDR6(SEQ ID No. 6), or aminoacids substituted with other aminoacids having equivalent chemical functions and properties, within said sequences SEQ ID No. 1 to SEQ ID No. 6.
