Hi, we try to establish a solid tumor model with the A20 (ATCC TIB-208) cell line in Balb/c mice (Charles River). We injected severeal doses (1x10^5 to 1x10^6; in 100µL 1x PBS or isotonic saline solution) subcutaneously at the hind limbs. But we hardly get the tumor rate which has been published so far. We are lucky if we get 50% in a batch. Even the time when solid tumors occur is very variable. Do You've any hints and clues why the rate is so bad and how to improve it? Or is there a difference between the published results that in most cases show a rate of 100% tumor development? Or do You know an alternative model that work in your hands? I'm happy about any news! Best, Sebastian