HOXA9 and chronic myelogenous leukemia, BCR-ABL1 positive: MSI2, but not HOXA9, was significantly over-expressed also in two other cases of Ph + blast crisis CML both harbouring additional cytogenetic aberrations (BC1 and BC2 in Figure 2a and b), with the following karyotypes: 46,XY,t(9;22)(q34;q11) [8]/49-52,XY,idem,+8,+t(9;22)(q34;q11),+13,+15,+21[cp6] (patient BC1), and 46XY,t(3;7)(p21;q32),t(9;22)(q34;q11)[15/15]) (patient BC2).