Moreover, the authors suggested an interaction between MM-related factors and the patient's genetic background in the development of bortezomib-induced PN, as several of single nucleotide polymorphisms (SNPs) were associated with early-onset bortezomib-induced PN (SNPs located in caspase 9, RDM1, ALOX12, IGF1R and LSM1 genes). The gene discussed is CASP9; the disease is poikiloderma with neutropenia.