PARP1 and leukemia: Although the LS neuroblastoma cells with the C/C genotype had the lowest PARP activity among all analysed neuroblastoma cell lines and Jurkat (leukaemic) cells also had the C/C SNP and low PARP activity, four other cell lines with very low PARP activity, namely, two leukaemia cell lines CCRF-CEM and TK6, thyroid carcionoma cell line ML-1 and immortalised bone marrow stromal cells HS-5, did not possess variant allele of T2444C.