PLXNA3 and neoplasm: While SEMA3F, 5A, 6A, and 6D expression is clearly higher in tumor cells, the opposite is true for SEMA4A and 6B. The semaphorin receptor genes PLXNA1, PLXNA3, NRP1, and NRP2 are expressed by both cell types, whereas PLXNB1 and PLXND1 expression is selective for tumor cells and TAMs, respectively.