NRP1 and systemic lupus erythematosus: However, to further explore BDCA-4 (gene symbol: NRP1 [Neuropilin-1]) and BDCA-2 (gene symbol: CLEC4C [C-type Lectin Domain Family 4 Member C]) expression in SLE, we analyzed raw RNA sequencing counts from a published study [27] available in the Gene Expression Omnibus (Supplementary Figure S5A,B).