SPTB and infection: In conclusion, the GWAS detected fetal association signals for SPTB and duration of pregnancy in the vicinity of SLIT2 and ROBO1. SLIT2 and ROBO1 were upregulated in SPTB placentas, and further functional studies confirmed that this signaling pathway has a role in regulation of the pathways associated with infection, inflammation, and immune response in trophoblast-derived cells.