Left panel: [Ce/Fe] vs. [M/H] colour-coded with the OC ages. Each [Ce/Fe] and [M/H] value is the mean of all the OC members. Vertical error bars are the mean dispersion in cerium abundances (star-to-star scatter), and the horizontal lines link the GSP-Spec [M/H] to the reference values. Central panel: [Ce/Fe] abundances with respect to the guiding radius colour-coded with age. The dashed line illustrates the derived radial gradient. Left panel: [Ce/Ca] ratio with respect to the metallicity colour-coded with the age.