A mixture of globotetraosylceramides; the major glycolipids in human erythrocytes; act as receptors for the Shiga toxins Stx1, Stx2, and Stx2e, the cytotoxic protein pierisin-1, and parvovirus B19; increase the expression of proteins responsible for enamel deposition in dental epithelial cells; levels of globotetraosylceramides are elevated in fibroblasts from patients with salt and pepper syndrome