ICOS and systemic lupus erythematosus: The IPA pathways involved include the iCOS-iCOSL Signaling in T Helper Cells (Figure 3A), Crosstalk between Dendritic Cells and Natural Killer Cells, Th1 and Th2 Activation Pathway, Systemic Lupus Erythematosus In B Cell Signaling Pathway, LPS/IL-1 Mediated Inhibition of RXR Function, Leukocyte Extravasation Signaling, Th2 Pathway, Th1 Pathway, Phenylethylamine Degradation I, and Xenobiotic Metabolism CAR Signaling Pathway.