Soleus muscle cross sections in control and unloaded WT, Nfkb1^–/–, and Bcl3^–/– mice. (A–F) Morphology of representative sections using H&E stain. (G–L) Representative cross sections from anti-laminin–stained soleus muscles. The anti-laminin–stained sections were used for measurement of mean fiber area. Scale bars: 50 μm.