Analysis of changes in IGHM or IRAK4 MAF following in vivo propagation of human CLL cell lines MEC1, C1, and HG3. (A) Indel analysis of the targeted region of the IRAK4 gene or (B) IGHM gene in injected and recovered leukemia cells isolated from subcutaneous tumor, PC, and spleen of xenografted NSG mice. The wild type allele is indicated by a red arrow, and mutant alleles are indicated by black arrows. (C-D) IRAK4 and IGHM MAF in injected leukemia cells and cells isolated from subcutaneous tumors, PCs, and spleens of NSG mice. The tumor cells were recovered 24 to 37 days after transplantation. Each circle represents an independent experiment. Statistical analysis was done with 1-way repeated measures ANOVA with Tukey test for multiple comparisons.