Thompson et al. first demonstrated the ability of GEP to correctly distinguish between ALK positive and ALK negative ALCL based on the differential expression of genes encoding signal transduction molecules (SYK, LYN, CDC37), transcription factors (including HOXC6 and HOXA3), and cell cycle regulators (CCND3 and CDKN2D) [45]. Here, ALK is linked to anaplastic large cell lymphoma.