- Synergistic induction of cytogenetic damage by the homo-aza-steroidal ester of p-bis(2-chloroethyl)aminophenylacetic acid in combination with caffeine in human lymphocytes in vitro and in Ehrlich ascites tumour cells in vivo. Petrou, C., Mourelatos, D., Dozi-Vassiliades, J., Catsoulacos, P. Mutat. Res. (1990)