Retrofection of p18 into four HMCL. Representative results are shown for retrofection of four HMCL with pVPG-0 or pVPG-p18 vector. A. Western blot containing extracts from uninfected or infected HMCL. Dilutions of L363 are shown to compare endogenous p18 expression with transfected cells: 1)100 μg uninfected OPM-2; 2)100 μg OPM-2.p18(15% EGFP+); 3)12.5 μg L363; 4)25 μg L363; 5)12.5 μg L363.p18 (puromycin selected); 6) 100 μg of JIM-3. B. Relative growth of infected cells that express EGFP after infection with pVPG-0 (only L363 is shown) or pVPG-p18 (all four HMCL), starting one day after infection (0 generations). The ordinate is the fraction of EGFP cells (normalized to the % EGFP positive cells one day after infection) and the abcissa is the number of generations of the total cell population. Symbols: diamond, L363 (pVPG-0); box, L363; horizontal line, JIM-3; triangle, OPM-2; open circle, KMS-12PE.