The present invention relates generally to substituted benzofurans, benzothiophenes, and indoles and their use as tubulin polymerisation inhibitors. wherein; X represents O, S, SO, SO 2 , Se, SeO, SeO 2 or NR where R is selected from H, O, optionally substituted acyl, optionally substituted alkenyl, optionally substituted alkyl, optionally substituted aryl, optionally substituted cycloalkenyl, optionally substituted cycloalkyl, optionally substituted heteroaryl, optionally substituted heterocyclyl, and optionally substituted sulfonyl; R 1C represents C 1-3 alkoxy, C 1-3 alkylthio, C 1-3 alkylamino, or C 1-3 dialkylamino; R 1D represents hydroxy or amino; L represents C=O, O, S, SO, SO 2 , Se, SeO, SeO 2 , C=NZ', or NR' where Z' is H, optionally substituted alkyl, optionally substituted aryl or optionally substituted amino; and where R' is selected from H, O, optionally substituted acyl, optionally substituted alkenyl, optionally substituted alkyl, optionally substituted aryl, optionally substituted cycloalkenyl, optionally substituted cycloalkyl, optionally substituted heteroaryl, optionally substituted heterocyclyl, or optionally substituted sulfonyl; The other variables are as defined in the claims.