My early work defined lumican, a keratan sulfate proteoglycan of connective tissue ECMs of the cornea, tendon, skin, cartilage. These studies predate completion of the Human Genome Project, necessitating the purification of the lumican protein, establishing its N-terminal amino acid sequence, isolating genomic and cDNA clones and Sanger sequencing of the lumican gene. Subsequently, we generated gene-targeted lumican-deficient mice that developed cloudy cornea, and skin and tendon fragility due to abnormal collagen fibril structure (Chakravarti, 1998). These studies identified a critical role for lumican in collagen fibril assembly, confirming prior biochemical predictions. This mouse model continues to be used by the community.