CAT and B-cell chronic lymphocytic leukemia: In CLL, although CAT mRNA levels were highly heterogeneous in both the two genotype groups (CV = 64.40% for the CC genotype; CV = 85.95% for the CT/TT genotypes), CLL cells harboring the T allele exhibited significantly higher average CAT mRNA levels compared with cells bearing the CC genotype (Fig. 3A).