Based on their different origins and functions, B cells can be divided into two types: B-1 cells and B-2 cells. B-2 cells are classical B lymphocytes that mainly exist in peripheral blood and lymphoid organs, accounting for approximately 45% of peripheral blood B lymphocytes. After first encountering an antigen, B-2 cells undergo clonal expansion and, with the help of T cells, produce high-affinity IgM antibodies. Learn more: B-2 Cells that Produce IgM Antibodies