Figure 3From: Reaction-Diffusion-Delay Model for EPO/TNF-α Interaction in articular cartilage lesion abatementStates of chondrocytes during stereotypical injury response. Healthy cells (C) become sick. Typically a healthy cell will first become catabolic (S T ) and either enter apoptosis (D A ), or become EPOR active (S A ). EPOR active cells may be saved by EPO to become healthy once again, or die (apoptosis).Back to article page