This invention provides lipids having: 1) a glycerol backbone; 2) a hydrocarbon chain, preferably saturated and containing 16 or 18 carbon atoms, attached to C-1 of the backbone by an ether linkage, 3) a methyl group attached to C-2 of the backbone, preferably by an ether linkage; and, 4) a sugar attached to C-3 of the glycerol backbone in either the alpha or beta anomeric configuration, the sugar being altered by modification of, or substitution for, one or more of its hydroxyl groups. Also provided herein are ether-lipid-containing compositions, as well as methods of administering such compositions to animals, for example, those afflicted with cancers, as well as various other diseases and disorders.