Bone Lesions in Molecular Subtypes of Multiple Myeloma

To the Editor: In a recent article in the Journal, Tian et al. showed the power of microarray data mining in finding new links between single genes (e.g., dickkopf1 [DKK1]) and clinical features of a disease (in the case of DKK1, bone lesions in multiple myeloma).1 We recently divided multiple myeloma into five molecular subtypes (called translocation and cyclin D [TC] types) on the basis of cyclin D1 messenger RNA expression (without an 11q13 translocation) and the presence of translocations in the immunoglobulin heavy-chain gene, from chromosome 14 to 11q13 or 6p21, to 4p16, and to 16q23 or . . .