Detection of endogenous FOS: Whole cell lysates of serum starved tumor cells (20.000 cells per lane) were applied to SDS-PAGE and transferred to a PVDF membrane. The immunoblot was probed with mab FOS-8B5 (0.5 ug/ ml) for 1h at RT and developed by ECL (exp. time: 30 sec). Lane 1: A431 Lane 2: A549 Lane 3: SKOV3 Lane 4: OVCAR5 Lane 5: HaCaT Lane 6: PC3 Lane 7: HeLa Lane 8: HepG2