We performed deep Ion Torrent-based sequencing (mean read depth 11,781X) for the MYD88 L265P mutation using DNA extracted from LCLs after 9 passages in vitro (9p) in 38 out of 46 individuals from WM families described above (23 WM and 15 MGUS), and in 117 individuals from a collection of familial multiple myeloma families (74 MM and 43 MGUS). Here, MYD88 is linked to plasma cell myeloma.