“…111 It is a common finding, for example, not only in PV, [53][54][55] but also in PMF [26][27][28]112 and may occur in ET, 114,115 chronic neutrophilic leukaemia, 62 myelodysplastic syndromes 113,114 and acute myeloid leukaemia, 115 although rarely in lymphoproliferative malignancies. 116,117 It is mostly found as an isolated event, although in approximately a quarter of cases it can occur with additional cytogenetic abnormalities including deletion 5q, monosomy 7, trisomy 8, deletions and translocations of 13q and trisomy 21. 117 The 20q breakpoints appear to be heterogeneous, as evidenced by the variable size of the deletion by standard cytogenetics, 118 FISH analysis 119 and by the early molecular studies, which demonstrated the variable retention of the SRC gene.…”