Subtype defining chromosomal rearrangements, some detectable by FISH/cytogenetic testing, are reported in three of the four genomic landscape papers and involve rearrangement of KMT2A [14, 17], MLLT10 [14, 16, 17], SPI1 [14, 17], NUP214/98 [14, 16], and ABL1 [16, 17], though, in T-ALL, only KMT2A, ABL1, and MYB rearrangements are routinely probed via FISH [23]. The gene discussed is ABL1; the disease is acute lymphoblastic leukemia.