OPN1SW and mixed phenotype acute leukemia: Several chromosomal rearrangements involving the NUP214 gene have been found in hematological malignancies; the most studied is t(6;9)(p23;q34)/DEK::NUP214 in AML [35], followed by NUP214::ABL1 in T-ALL [36,37,38,39,40], BCP-ALL [41,42,43], and AML [44], and t(9;9)(q34.11;q32.13)/del(9)(q34.11q32.13)/SET::NUP214 in acute undifferentiated leukemia [45,46], T-ALL [47,48,49], AML [48,50], MPAL [51], and CML [52].