Anti-proliferative and apoptotic effects of rapamycin in vitro. a. G1 cell cycle arrest detected by flow cytometry after 72 h rapamycin treatment (50 ng/ml) in KMH2 Hodgkin-lymphoma cells. b. The apoptotic effect of rapamycin is time dependent in KMH2 cells (flow cytometry, *:p<0.05). c. Rapamycin treatment increased the apoptotic effect of chemotherapeutic agents in HL cell lines after 24 h. A representative experiment in KMH2 cells is shown here. (R: rapamycin 50 ng/ml, D: doxorubicin 0.2 μM, V: vincristine 10 nM, Eto: etoposide 1 μM; *:p<0.05).