(A) Starved MEFs were reseeded on hydrogels with 10% FBS. Cell lysates were collected and analyzed by western blotting. (B) Starved MEFs infected with adenoviruses encoding LacZ or cyclin D1 (30-300 MOI) were reseeded on hydrogels with 10% FBS. Cells were collected at 24 h and analyzed by western blotting. (C) Starved MEFs infected with adenoviruses encoding GFP (1000 MOI), cyclin D1 (100, 300, and 1000 MOI), or HPV-E7 (100, 300, and 1000 MOI) were reseeded on high (H) and low (L) stiffness hydrogels and incubated with 10% FBS. S phase entry was measured 24 h after plating by immunostaining for Ki-67. (D) Starved MEFs were reseeded on hydrogels with 10% FBS. INK4 mRNA levels were measured by QPCR. (E) Starved MEFs infected with adenoviruses encoding cyclin D1 (100 MOI) and either LacZ or GFP-FRNK were reseeded in 10% FBS with BrdU. Cells were fixed at 24 h for analysis of BrdU incorporation. (F) MEFs infected with adenoviruses encoding GFP, CD2-FAK, cyclin D1 (100 MOI), or cyclin D1 & CD2-FAK were starved and plated on the high and low stiffness substrata and stimulated with 10% FBS for 24 h; S phase entry was determined by BrdU incorporation.