A B cell is not considered an effector cell. B cells are a type of lymphocyte that plays a crucial role in the adaptive immune response, specifically in humoral immunity. They are responsible for producing antibodies, which are effector molecules, but they themselves are not classified as effector cells. Effector cells are typically considered to be activated T cells, such as cytotoxic T cells and helper T cells, as well as some innate immune cells like macrophages and natural killer cells.
