Gas metallicity vs. stellar mass from a collection of different surveys and categories of sources in the local and high-redshift Universe (as reported in the legend; Hirschauer et al. 2022; Berg et al. 2022; Izotov et al. 2018, 2019; Nishigaki et al. 2023; Yang et al. 2017a,b; Nakajima et al. 2023; Matthee et al. 2023; Rhoads et al. 2023; Curti et al. 2023). The star-forming region described in this work – LAP1 at z = 6.639 and its subcomponent B – are marked with stars in the bottom-left corner of the figure and lie below the extremely metal-poor plateau identified to date (EMPG), approximately indicated with a horizontal shaded stripe.