Figure 1.
Transforming activity of Indian hedgehog homolog (IHH). Mouse 3T3 cells were infected with viruses encoding IHH or v‐Ras or with the empty virus (Mock), and were then cultured for 5 days for the analysis of focus formation (top panels; scale bars = 1 mm). The same batches of 3T3 cells were also assayed for anchorage‐independent growth in soft agar over 17 days (middle panels) and for tumorigenicity in nude mice over 3 weeks (bottom panels). Tumors formed in the shoulders of mice injected subcutaneously with 1 × 105 cells are indicated by red circles. The frequency of tumor formation (tumors/injection) is also indicated.