MOLECULE

1 . A method for selecting for cells transduced to express a nucleic acid sequence of interest (NOI), which comprises the following steps:

(a) transducing a population of cells with a vector co-expressing (i) the NOI and (ii) a nucleic acid sequence which encodes dominant negative Fas and

exposing the cells to FasL;

(b) transducing a population of cells with a vector co-expressing (i) the NOI, (ii) nucleic acid sequence which encodes dominant negative Fas and (iii) a nucleic acid sequence encoding FasL, and culturing the cells; or

(c) co-transducing a population of cells with a first vector co-expressing (i) a CAR or TCR, and (ii) dominant negative Fas, and with a second vector expressing FasL, and culturing the cells.

2 - 3 . (canceled)

4 . A method according to claim 1 , wherein the dominant negative Fas comprises the Fas extracellular domain but has a truncated or mutated death domain so that it does not bind FADD.

5 . A method according to claim 4 , wherein the dominant negative Fas comprises the Fas extracellular domain and an endodomain from a TNF receptor.

6 . A method according to claim 5 , wherein the dominant negative Fas comprises an endodomain from decoy receptor 2 (DcR2), GITR, CD30, XEDAR, CD40, CD27, HVEM, BCMA, 4-1BB or Fn14.

7 - 10 . (canceled)

11 . A method according to claim 1 wherein, in step (b), FasL is soluble FasL, FasL bound to a solid substrate, or FasL expressed on the surface of a cell.

12 - 21 . (canceled)

22 . A method according to claim 1 , wherein the NOI encodes a chimeric antigen receptor (CAR) or a transgenic T cell receptor (TCR).

23 . A method according to claim 1 , wherein the NOI inhibits expression of endogenous T-cell receptor (TCR).

24 . (canceled)

25 . A cell engineered to express dominant negative Fas and (b) FasL

26 . (canceled)

27 . A cell according to claim 25 , which also expresses

(c) a chimeric antigen receptor (CAR) or a transgenic T cell receptor (TCR) and/or a nucleic acid sequence of interest (NOI) which inhibits expression of endogenous T-cell receptor (TCR).

28 - 33 . (canceled)

34 . A pharmaceutical composition which comprises plurality of cells selected by a method according to claim 1 .

35 . A method for treating cancer which comprises the step of administering a pharmaceutical composition according to claim 34 to a subject.

36 - 42 . (canceled)

43 . A nucleic acid construct for expression in a cell which comprises:

a nucleic acid sequence encoding a chimeric antigen receptor (CAR) or a transgenic T cell receptor (TCR) and/or a nucleic acid sequence of interest (NOI) which inhibits expression of endogenous T-cell receptor (TCR);

a nucleic acid sequence encoding dominant negative Fas; and optionally

a nucleic acid sequence encoding FasL

44 . A vector which comprises a nucleic acid construct according to claim 43 .

45 . (canceled)

46 . A kit of vectors which comprises:

a first vector comprising a nucleic acid sequence encoding a chimeric antigen receptor (CAR) or a transgenic T cell receptor (TCR) and/or a nucleic acid sequence of interest (NOI) which inhibits expression of endogenous T-cell receptor (TCR); and a nucleic acid sequence which encodes dominant negative Fas; and

a second vector comprising a nucleic acid sequence encoding FasL

47 . A method for making a cell according to claim 25 which comprises the step of introducing into a cell ex vivo: (a) a nucleic acid sequence which encodes dominant negative Fas; and (b) a nucleic acid sequence encoding FasL.

48 . A pharmaceutical composition which comprises plurality of cells according to claim 25 .

49 . A method for treating cancer which comprises the step of administering a pharmaceutical composition according to claim 48 to a subject.