Treatments for conditions involving detrimental activity of the enzyme core2 GIcNAc - T are provided using compounds of the formula (I) wherein Ris H, -OH, C alkoxy, -NRR, or Sac 1; Ris H, -OH, C alkoxy or Sac 2; R is H, -OH, Calkoxy or Sac 3; R is H, C alkyl, C hydroxyalkylor C-alkoxy- C -alkyl; R is H, Calkyl or C acyl; Ris H, C alkyl or Cacyl; Sac 1 Sac 2 and Sac 3 are independently selected saccharide moieties; andZ is a steroid moiety; or a pharmaceutically acceptable salt, ether or ester formthereof