Flow cytometry (FCM) revealed 28% of tumor cells in the bone marrow with a phenotype compatible with SMZL (CD45+, CD19+, CD5−, CD22+, CD23−/+, CD103−, CD25−, FMC7+, CD11c−, CD20+, CD10−, CD38+, and BCL-2−). Here, MS4A1 is linked to neoplasm.