Cell

1 . A T cell which co-expresses a first chimeric antigen receptor (CAR) and second CAR at the cell surface, each CAR comprising:

(i) an antigen-binding domain;

(ii) a spacer

(iii) a trans-membrane domain; and

(iv) an endodomain;

wherein the first CAR binds CD19 and the second CAR binds CD20.

2 - 4 . (canceled)

5 . A T cell according to claim 1 which comprises more than two CARs such that it is specifically stimulated by a cell, such as a target cell, bearing a distinct pattern of more than two antigens.

6 . A nucleic acid sequence encoding first and second chimeric antigen receptors (CARs) each CAR comprising:

(i) an antigen-binding domain;

(ii) a spacer

(iii) a trans-membrane domain; and

(iv) an endodomain;

wherein the first CAR binds CD19 and the second CAR binds CD20.

7 . A nucleic acid sequence according to claim 6 , which has the following structure:

AgB1-spacer1-TM1-endo1-coexpr-AbB2-spacer2-TM2-endo2

in which

AgB1 is a nucleic acid sequence encoding the antigen-binding domain of the first CAR;

spacer 1 is a nucleic acid sequence encoding the spacer of the first CAR;

TM1 is a a nucleic acid sequence encoding the transmembrane domain of the first CAR;

endo 1 is a nucleic acid sequence encoding the endodomain of the first CAR;

coexpr is a nucleic acid sequence enabling co-expression of both CARs

AgB2 is a nucleic acid sequence encoding the antigen-binding domain of the second CAR;

spacer 2 is a nucleic acid sequence encoding the spacer of the second CAR;

TM2 is a a nucleic acid sequence encoding the transmembrane domain of the second CAR;

endo 2 is a nucleic acid sequence encoding the endodomain of the second CAR;

which nucleic acid sequence, when expressed in a T cell, encodes a polypeptide which is cleaved at the cleavage site such that the first and second CARs are co-expressed at the T cell surface.

8 . A nucleic acid sequence according to claim 7 , wherein coexpr encodes a sequence comprising a self-cleaving peptide.

9 . A nucleic acid sequence according to claim 7 or 8 , wherein alternative codons are used in regions of sequence encoding the same or similar amino acid sequences, in order to avoid homologous recombination.

10 - 12 . (canceled)

13 . A vector comprising a nucleic acid sequence according to claim 6 .

14 . A retroviral vector or a lentiviral vector or a transposon according to claim 13 .

15 . A method for making a T cell according to claim 1 , which comprises the step of introducing into a T cell: a nucleic acid sequence according to claim 6 or a vector according to claim 13 .

16 . A method according to claim 15 , wherein the T cell is from a sample isolated from a subject.

17 . A pharmaceutical composition comprising a plurality of T cells according claim 1 .

18 . A method for treating and/or preventing a disease, which comprises the step of administering a pharmaceutical composition according to claim 17 to a subject.

19 . A method according to claim 18 , which comprises the following steps:

(i) isolation of a T cell-containing sample from a subject;

(ii) transduction or transfection of the T cells with: a nucleic acid sequence according to claim 6 ; or a vector according to claim 13 ; and

(iii) administering the T cells from (ii) to a the subject.

20 . A method according to claim 18 , wherein the disease is a cancer.

21 - 26 . (canceled)

27 . A natural killer (NK) cell which co-expresses a first chimeric antigen receptor (CAR) and second CAR at the cell surface, each CAR comprising:

(i) an antigen-binding domain;

(ii) a spacer

(iii) a trans-membrane domain; and

(iv) an endodomain;

wherein the first CAR binds CD19 and the second CAR binds CD20.

28 . A cell composition comprising CAR expressing T cells according to claim 1 and/or CAR expressing NK cells according to claim 27 made by transducing a blood-sample ex vivo with a nucleic acid encoding the first and second CARs.