Cell line growth in vivo. (

<p>A) Spherical subcutaneous mass (arrow) in Rag-2^−/− γ-chain^−/− mice 36 days after VR09 cell line injection (representative case). (B) Timing of tumor development <i>in vivo</i> (6 mice s.c. injected with 5×10⁶ cells/mouse).