Slopes of the metallicity gradients (Δα) of the AGN (pink points) and SF (gray stars) galaxies as a function of the luminosity of the [O III] λ5007 line within an aperture with r ∼ 1 kpc (logL [O III]λ5007_{r < 1 kpc}) and the host galaxy stellar mass. Pink and gray contours represent density curves computed by a KDE. No clear correlation is observed in both the Δα – L[O III]λ5007 diagram and Δα − logM_*/M_⊙ diagrams in the SF and AGN samples, as supported by the Spearman rank-order correlation coefficient reported in the legend.