Figure 2. Egfr mutant follicles did not progress through catagen following cyclophosphamide.

Hematoxylin and eosin stained sections from mutant (panels on right) and control (panels on left) mice after cyclophosphamide (B-D) or vehicle (A). Vehicle mice displayed anagen 2d post-injection (A, arrowheads). Egfr controls (B left) exhibited follicular distortion (arrowhead) and regression, while mutants (B right) had follicular distortion (arrowhead) at 2 d after cyclophosphamide. By 4d, controls (C left) displayed late dystrophic catagen, while mutants (C right) maintained elongated follicles (arrowhead). Controls initiated secondary recovery with anagen by 8 d (D left), indicated by the bulb position at dermis and subcutis border (arrowhead). Mutant follicles retained hair at 8 d (D right, arrowhead). Scale bar indicates 100 µm.