Soft X-ray (0.5–2 keV) luminosity versus temperature kT of the ICM in massive structures across redshift. Symbols show galaxy clusters from Bulbul et al. (2019) (green squares), O’Hara et al. (2007) (orange triangles), Mittal et al. (2011) (magenta crosses), and high-redshift clusters from the literature (cyan triangles; Stanford et al. 2001; Fabian et al. 2001; Mathur & Williams 2003; Andreon & Huertas-Company 2011; Tozzi et al. 2015; Mastromarino et al. 2024). The red square marks the Spiderweb protocluster hot X-ray halo (L24), while the red circle shows the value for the X-ray halo in this work (MQN01) within a radius of 8″, respectively. The background density distributions represent the conservative MCMC posterior accounting for systematics (Section 4.3).