More specifically, MHC-I signaling was prominent in ligand–receptor interactions of HLA class I molecules with CD8A, CD8B and KLRK1, while Galectin signaling was primarily mediated between LGALS9 (a biomarker in SLE pathogenesis50) and CD45 (Fig. 3h). Here, PTPRC is linked to systemic lupus erythematosus.