long-term protection. LLPC can maintain antibody production for decades or even for the lifetime of an individual, and, unlike B cells, LLPC do not need antigen restimulation to generate antibodies. Human LLPC population can be identified as CD19^- CD38^hi CD138⁺ cells.

The long-term survival of LLPC are dependent on a specific environment in the bone marrow, the plasma cell survival niche. Removal of an LLPC from