E2F1 and osteosarcoma: As can be seen in Figure 1B, activation of the ectopic E2F1 by addition of its inducer, 4-hydroxytamoxifen (OHT), resulted in a significant increase in ERIC RNA levels in the U2OS and H1299 lines described above, as well as another human osteosarcoma cell line, SAOS-2, and WI38 human embryonic lung fibroblasts.