CRLF2 and acute lymphoblastic leukemia: The genotypic and allelic frequencies of risk homozygotes (AA and CC) and risk alleles (A and C) for both SNPs were higher in patients with CRLF2-OE (53.8% and 51%/0.72 and 0.72, respectively), followed by the total pre-B ALL patients (38.5% and 38.0%/0.62 and 0.63) and the group of patients without CRLF2-OE (28.6% and 30.1%/0.54 and 0.56).