GangliosideGQ1b is a tetrasialoganglioside that contains two sialic acid residues linked to an inner galactose unit. It stimulates phosphorylation of several ecto-type protein kinase substrates on the surface of GOTO human neuroblastoma cells when used at a concentration of 5 nM. GangliosideGQ1b promotes differentiation of murine embryonic stem cells (mESCs) to neuronal precursor and glial cells via activation of the ERK1/2 pathway. It also induces differentiation of murine keratinocytes through phosphoinositide turnover. GangliosideGQ1bmixture contains gangliosideGQ1b molecular species with C18:1 and C20:1 sphingoid backbones.