The density of two types of these cells forms the basis of a classification scheme proposed by Jérôme Galon, which ranges from I0 to I4 and may outperform traditional TNM staging. A type of these cells requires B7 proteins to provide costimulatory signals that prevent incomplete activation, which can lead to anergy. A type of these cells begins (10[1])to express FOXP3 after receiving intermediate strength signals during negative selection. These cells, which include (10[1])a “regulatory” subtype, have receptors (10[1])that bind to MHCs found on antigen-presenting cells. CD4-positive (10[1])and CD8-positive types of these cells, which mature in the thymus, are respectively known as these cells’ helper and killer varieties. (10[1])For 10 points, the adaptive immune system primarily consists of B cells and what other white blood cells? ■END■