I am not sure if I understand your question completely, but if you derived the cells from a C57Black mouse, it should in theory be feasible to put them back subcutaneously on C57Black mice. But if you get tumors is not only a question whether the mouse rejects the cells, but also if the cells are able to form tumors. If you have checked for that in nude mice, I would try on C57Bl, but I would not be sure that you can use any mouse cell from any mouse background on C57. My impression is that they need to be syngene (from same background) Hope that was what you asked for.

Hi Maria, hi Brian, Thank you very much! Indeed, I have done tumor model by injecting the mouse cells (MC38) to C57 mouse, successfully, but I am wondering whether what I have done is professional, is it acceptable do it like this? Thank you.

Mouse models for invivo experiments all depends upon whether you are using human or murine cell lines. wild type C57bL6 Mice have been know to be radio sensitive and best model for murine cell lines ( Mouse Derived).

Recently the role of microenvironment has gained significant attraction and its better to do ortho topic implantation instead of subcutaneous injections of tumor models so that you can translate better these results to clinical trials.

most important is that your institutional animal ethical review committee must have approved all protocols

I agree to Dr. Arshads comment orthotopic implatation is the way to go, if doable. If you go for the sc. implant anyway you should make sure that the amount of cells is so small that you can follow the tumor growth without reaching the allowed size (by your ethical commitee) too quikly (off cause dependent of what you want to explore). You also need to be aware of the inflammatory proces that can cause edema at the injection site in the first 2-5 dayswhich is not to be meassured as tumor growth.