FOS and aneurysmal bone cyst: In ABC LN, early activated CD8+ T-cells (TEA-1) expressed Fos/Jun genes (AP-1) and Dusp1, IFN-I-stimulated genes and chemokines (Ccl5 and Xcl1). AP-1 genes and Dusp1 may contribute to T-cell anergy, triggered by incomplete T-cell receptor engagement or deficient CD28 signaling in the presence of Tregs.