/The fraction of lineages that contain an unmutated germline variant will depend on a variety of experimental factors, including the age and health status of the subject from which the cells were sampled, tissue of origin and enrichment protocol (e.g. for specific markers) that was applied prior to sequencing. However, in samples consisting of unsorted B cells, these numbers are large: naive B cells represent 50-90% of all B cells in the peripheral blood, lymph nodes, tonsils, and the bone marrow.