Remember that secondary lymphoid organs include the spleen, lymph nodes, and MALT. Dense aggregations of MALT can be found in which layer of the gastrointestinal tract?

Remember that secondary lymphoid organs include the spleen, lymph nodes, and MALT. Dense aggregations of MALT can be found in which layer of the gastrointestinal tract?
Reevaluate the thymus classification as a lymphoid organ