passages.id: split_6_test_2853_passage
passages.type: progene_text
passages.text: Although the effects of mitogens on the synthesis of interleukin-2 ( IL-2 ) and IL-2 receptor ( IL-2r ) have been described , a detailed in situ analysis of the spatio - temporal changes of the expression of the IL-2 gene and the three IL-2r components in lymphoid tissues is still missing .