Metallicity distribution of the stars of Liller 1 obtained from recent surveys. Top panel: results of this work (from CRIRES+ at VLT), F24 (from NIRSPEC at Keck), and those of Alvarez Garay et al. (2024a, from X-shooter at VLT). Central panel: iron distribution obtained from MUSE at VLT by Crociati et al. (2023). Bottom panel: [Fe/H] distribution of the total sample obtained by combining the different datasets and counting 105 stars.