There is provided a chimeric antigen receptor (CAR) comprising a CD19-binding domain which comprises a) a heavy chain variable region (VH) having complementarity determining regions (CDRs) with the following sequences: (SEQ ID No. 1) CDR1 - GYAFSSS; (SEQ ID No. 2) CDR2 - YPGDED (SEQ ID No. 3) CDR3 - SLLYGDYLDY;  and b) a light chain variable region (VL) having CDRs with the following sequences: (SEQ ID No. 4) CDR1 - SASSSVSYMH; (SEQ ID No. 5) CDR2 - DTSKLAS (SEQ ID No. 6) CDR3 - QQWNINPLT.  There is also provided a cell comprising such a CAR, and the use of such a cell in the treatment of cancer, in particular a B cell malignancy.