Among these, CLL MLPA analysis identified a complex amplification on 18q21.1 containing the SMAD4 gene, and a gain (trisomy) of chromosome 19, as well as small intragenic deletions at the 19q13.43 CHMP2 and 19p13.2 CDKN2D loci. This evidence concerns the gene SMAD4 and B-cell chronic lymphocytic leukemia.