A: A schematic of the Adamts18 knockout mouse acquired from KOMP showing the deleted region and homologous recombination to insert a LacZ sequence in its place (adapted from KOMP’s description of the mouse). B: The genotyping results of pups born from Adamts18+/− crosses demonstrating Mendelian inheritance of the wildtype, Adamts18+/−, and Adamts18−/− genotypes (numbers on bar graph represent the number counted). C-J: Wildtype (C, E, G, I) and Adamts18−/− (D, F, H, J) lungs at various stages stained with cytokeratin. The 5 lung lobes are highlighted in C and D: cranial = green, medial = pink, caudal = yellow, accessory = purple, left = blue. K, L: Freshly dissected wildtype (K) and Adamts18−/− (L) adult lungs. Line = 500μm.