Fig. 1.

Combined collagen and $\alpha$-SMA staining in normal [(a) and (c)] and IPF [(b) and (d)] tissues. The top row gives SHG images only and the bottom row is an overlap of SHG (grayscale) and TPEF (red) for $\alpha$-SMA, identifying fibrotic regions. $\mathrm{S}\text{cale bar}=30\mu \mathrm{m}$.