The LTK gene is located on 15q15.1, but although chromosome 15 is frequently triploid in hyperdiploid myeloma patients, we did not find increased LTK expression due to chromosomal amplification (p = 0.4874, one-way ANOVA, Supplementary Fig. S1C), nor did we find any correlation between LTK mRNA levels and secreted M-protein (data not shown). This evidence concerns the gene LTK and plasma cell myeloma.