Clusters hosting an IMBH at z = 0 in Model A (left panel) and Model B (right panel) compared to different classes of IMBH host candidate observations. We note that the masses reported for low-mass AGNs refer to the host galaxy mass (up to ∼ 100 times higher than the mass of the galactic nuclei). The gray dashed line shows the theoretical prediction for the initial mass of an IMBH seeded via stellar collisions (Eq. (3) in the left panel and Eq. (5) in the right panel).