Beta-1,3-N-acetylglucosaminyltransferase involved in the synthesis of poly-N-acetyllactosamine. Has activity for type 2 oligosaccharides. . This is the function of ENSG00000176383 (B3GNT4, UDP-GlcNAc:betaGal beta-1,3-N-acetylglucosaminyltransferase 4).