. "\"The process whose specific outcome is the progression of the thymus over time, from its formation to the mature structure. The thymus is a symmetric bi-lobed organ involved primarily in the differentiation of immature to mature T cells, with unique vascular, nervous, epithelial, and lymphoid cell components.\" [GOC:add, ISBN:0781735149]" . . "thymus development" . "Note that this term is reserved for annotation of gene products involved in the formation of the thymus itself, not for gene products involved in T cell differentiation in the thymus or elsewhere." . .