ALK and anaplastic large cell lymphoma: This discrepancy could reflect the variability of (i) ALCL models used in these studies—ALK(+) cell lines: SU-DHL-1, KARPAS-299, SR-786, SUP-M2/TS, JB-6, L82, KiJK, DEL, Pio and COST; ALK(−) cell lines: FE-PD, Mac1 and Mac2A [36]; Formalin-Fixed/Paraffin-Embedded (FFPE) tumor samples from both ALK(+) and ALK(−) ALCL and NPM/ALK transgenic mice—and (ii) methods employed to detect miRNA (microarrays, next generation sequencing or real time RT-PCR analyses).