Expression of endogenous PiT1 in MC3T3-E1 cells. MC3T3-E1 cells were seeded at 5,000 and 50,000 cells/cm2 in 4-well plates and 2 days after seeding, the mRNA levels of mPiT1 were analyzed by qRT-PCR. Each column represents cell lysates from three wells and triplicate qRT-PCR analyses of each cell lysate. The mPiT1 mRNA levels are standardized to B2M mRNA levels. Data are means ± SD.* indicates statistically significantly different from MC3T3-E1 cells seeded at 5,000 cells/cm2, p < 0.05.