Fig. 5. Constitutive expression of MMP-2, MT1-MMP and TIMP-2 mRNA during lung development. Lung sections from normal fetuses were taken at E12.5. For ISH analysis the following antisense probes were used: (a) MMP-2, (b) MT1-MMP, (c) TIMP-2, (d) MMP-9, (e) MMP-3, (f) TIMP-1. Note the presence of message in (a,b,c) and its absence in (d,e,f). Arrows point to the presence and arrowheads to the absence of message. Bar, 200 µm (a-f).