Rethinking the potential roles of mast cells in skin wound healing and bleomycin-induced skin fibrosis.

Skin wound healing and bleomycin-induced skin fibrosis are thought to reflect complex interactions among diverse cell types. Several lines of evidence have implicated mast cells in these tissue responses. However, data from Willenborg et al. (this issue) and from three other groups suggest that, in at least these examples of cutaneous tissue remodeling, mast cells may not have nonredundant roles.