The +1q gene expression signature comprised 51 genes and included known drivers of MM pathogenesis that have already been linked to +1q MM such as ILF216, as well as a number of genes that so far have not been associated with +1q MM like CTSS (cathepsin S), a cysteine protease involved in the recruitment of immunosuppressive myeloid cells18,19 (Fig. 2l and Supplementary Table 4). Here, CTSS is linked to Miyoshi myopathy.