A kit comprising bispecific antibody molecule which comprises (i) a first binding domain binding an antigen on CD8+ T-cells that does not naturally occur in or on CD8+ T-cells; and (ii) a second binding domain binding a tumor-specific antigen naturally occurring on the surface of a tumor cell; and a nucleic acid encoding the antigen that does not naturally occur in or on CD8+ T-cells for transducing said CD8+ T-cells obtained from a subject to be treated, wherein said antigen that does not naturally occur in or on CD8+ T-cells is selected from the group consisting of cripto, CD9, CD10, CD11, CD12, CD13, CD14, CD15, CD16, CD17, CD18, CD19, CD20, CD21, CD22, CD23, CD24, CD25, CD26, CD27, CD28, CD29, CD30, CD31, CD32, CD33, CD34, CD35, CD36, CD37, CD38, CD39, CD40, CD41, CD43, CD46, CD48, CD49, CD50, CD51, CD54, CD55, CD56, CD57, CD59, CD61, CD63, CD64, CD66, CD67, CD68, CD70, CD72, CD74, CD75, CD76, CD77, CD79, CD81, CD82, CD83, CD84, CD87, CD88, CD89, CD90, CD91, CD92, CD93, CD94, CD95, CD97, CD98, CD99, CD100, CD101, CD102, CD103, CD104, CD105, CD106, CD107, CD108, CD109, CD110, CD111, CD112, CD113, CD114, CD115, CD116, CD117, CD118, CD119, CD121, CD123, CD124, CD125, CD126, CD130, CD131, CD133, CD134, CD135, CD136, CD137, CD138, CD140, CD141, CD142, CD143, CD144, CD146, CD147, CD148, CD151, CD153, CD155, CD156, CD157, CD158, CD159, CD160, CD161, CD162, CD163, CD164, CD166, CD167, CD168, CD169, CD170, CD171, CD172, CD177, CD178, CD179, CD180, CD181, CD182, CD183, CD184, CD185, CD186, CD191, CD192, CD193, CD200, CD201, CD204, CD206, CD207, CD208, CD209, CD217, CD218, CD220, CD221, CD222, CD223, CD224, CD225, CD226, CD227, CD228, CD230, CD231, CD232, CD233, CD234, CD236, CD238, CD239, CD241, CD242, CD243, CD244, CD246, CD248, CD249, CD252, CD253, CD254, CD256, CD257, CD258, CD261, CD262, CD263, CD264, CD265, CD266, CD267, CD268, CD269, CD270, CD271, CD276, CD277, CD280, CD281, CD282, CD283, CD284, CD286, CD288, CD289, CD290, CD292, CD294, CD295, CD296, CD297, CD298, CD299, CD300, CD301, CD302, CD303, CD304, CD305, CD306, CD309, CD312, CD314, CD315, CD316, CD317, CD318, CD319, CD320, CD321, CD322, CD324, CD325, CD326, CD327, CD328, CD329, CD331, CD332, CD333, CD334, CD335, CD336, CD337, CD338, CD339, CD340, CD344, CD349, CD350, CD351, CD352, CD353, CD354, CD355, CD357, CD358, CD360, CD361, CD362, CD363, EGFR and TSH-R, wherein said antigen that naturally occurs on the surface of tumor cells is selected from the group consisting of EpCAM, HER-1, HER-2, HER-3, CD20, CD22, CD33, CD52, CA-12-5, HLA-DR, MUC-1 (mucin), A33-antigen, PSMA (prostate specific membrane antigen), Transferrin-receptor, Tenascin and CA-IX. bispecific antibody molecule which comprises (i) a first binding domain binding an antigen on CD8+ T-cells that does not naturally occur in or on CD8+ T-cells; and (ii) a second binding domain binding a tumor-specific antigen naturally occurring on the surface of a tumor cell; and (i) a first binding domain binding an antigen on CD8+ T-cells that does not naturally occur in or on CD8+ T-cells; and (ii) a second binding domain binding a tumor-specific antigen naturally occurring on the surface of a tumor cell; and a nucleic acid encoding the antigen that does not naturally occur in or on CD8+ T-cells for transducing said CD8+ T-cells obtained from a subject to be treated, wherein said antigen that does not naturally occur in or on CD8+ T-cells is selected from the group consisting of cripto, CD9, CD10, CD11, CD12, CD13, CD14, CD15, CD16, CD17, CD18, CD19, CD20, CD21, CD22, CD23, CD24, CD25, CD26, CD27, CD28, CD29, CD30, CD31, CD32, CD33, CD34, CD35, CD36, CD37, CD38, CD39, CD40, CD41, CD43, CD46, CD48, CD49, CD50, CD51, CD54, CD55, CD56, CD57, CD59, CD61, CD63, CD64, CD66, CD67, CD68, CD70, CD72, CD74, CD75, CD76, CD77, CD79, CD81, CD82, CD83, CD84, CD87, CD88, CD89, CD90, CD91, CD92, CD93, CD94, CD95, CD97, CD98, CD99, CD100, CD101, CD102, CD103, CD104, CD105, CD106, CD107, CD108, CD109, CD110, CD111, CD112, CD113, CD114, CD115, CD116, CD117, CD118, CD119, CD121, CD123, CD124, CD125, CD126, CD130, CD131, CD133, CD134, CD135, CD136, CD137, CD138, CD140, CD141, CD142, CD143, CD144, CD146, CD147, CD148, CD151, CD153, CD155, CD156, CD157, CD158, CD159, CD160, CD161, CD162, CD163, CD164, CD166, CD167, CD168, CD169, CD170, CD171, CD172, CD177, CD178, CD179, CD180, CD181, CD182, CD183, CD184, CD185, CD186, CD191, CD192, CD193, CD200, CD201, CD204, CD206, CD207, CD208, CD209, CD217, CD218, CD220, CD221, CD222, CD223, CD224, CD225, CD226, CD227, CD228, CD230, CD231, CD232, CD233, CD234, CD236, CD238, CD239, CD241, CD242, CD243, CD244, CD246, CD248, CD249, CD252, CD253, CD254, CD256, CD257, CD258, CD261, CD262, CD263, CD264, CD265, CD266, CD267, CD268, CD269, CD270, CD271, CD276, CD277, CD280, CD281, CD282, CD283, CD284, CD286, CD288, CD289, CD290, CD292, CD294, CD295, CD296, CD297, CD298, CD299, CD300, CD301, CD302, CD303, CD304, CD305, CD306, CD309, CD312, CD314, CD315, CD316, CD317, CD318, CD319, CD320, CD321, CD322, CD324, CD325, CD326, CD327, CD328, CD329, CD331, CD332, CD333, CD334, CD335, CD336, CD337, CD338, CD339, CD340, CD344, CD349, CD350, CD351, CD352, CD353, CD354, CD355, CD357, CD358, CD360, CD361, CD362, CD363, EGFR and TSH-R, wherein said antigen that naturally occurs on the surface of tumor cells is selected from the group consisting of EpCAM, HER-1, HER-2, HER-3, CD20, CD22, CD33, CD52, CA-12-5, HLA-DR, MUC-1 (mucin), A33-antigen, PSMA (prostate specific membrane antigen), Transferrin-receptor, Tenascin and CA-IX.