Professor Line was one of the early pioneers of atmospheric retrieval methods applied to some of the first transiting exoplanet spectra/photometry. His works on retrieval methods have driven the exo-atmosphere retrieval subfield (as well as the brown dwarf retrieval sub-field), through the development of Bayesian-best practices, temperature profile parameterizations, and multi-dimensional considerations. Line is PI/Co-I on several HST/JWST observing and theory proposals per year. Furthermore, Line was the co-developer/pioneer of the atmospheric retrieval method for high resolution cross-correlation spectroscopy with ground-based telescopes. His recent Nature publication demonstrated that 8 m class ground-based telescopes with moderate resolution spectrographs (eg., R 45K) could produce absolute molecular abundance constraints in hot Jupiter atmospheres comparable, if not better than, expected from JWST. He is currently leading over 120 hrs of ground based high resolution observing time and is a Co-I on nearly 100 more.