The Planetary Fourier Spectrometer (PFS, [1]) on Mars Express (MEx, [2]) has been observing the Martian atmosphere since January of 2004, Ls = 331.18° of MY 26. It has now provided nearly continuous monitoring of conditions in the Martian atmosphere for over 15 years and it is still performing measurements at the time of writing. We present retrievals of atmospheric parameters, such as temperature vertical profiles, surface temperatures, and column-integrated optical depth of suspended dust and water ice, as well as column-integrated abundance of carbon monoxide (CO) and water vapor (H2O), through radiative transfer modeling of thermal- and near-infrared spectra taken by the PFS. Joint observations between the Nadir and Occultation for Mars Discovery (NOMAD) and the Atmospheric Chemistry Suite (ACS) packages onboard ExoMars Trace Gas Orbiter (TGO), and the PFS are currently being planned and executed, allowing for intercomparison and intercalibration of spectra, as well as exploitation of synergies and complementarities for the retrieval of minor species, suspended aerosols, and other atmospheric parameters.