Structural model of Ferritin protein complex generated from PDBID 6I36 using Molstar.org
Sliced in PrusaSlicer 2.9.3 into individual chains and assembled (with the help of glue)

Ferritin action 
Ferritin superfamily protein cages reversibly synthesise internal biominerals, Fe2O3·H2O. Fe(2+) and O2 (or H2O2) substrates bind at oxidoreductase sites in the cage, initiating biomineral synthesis to concentrate iron and prevent potentially toxic reaction products from Fe(2+)and O2 or H2O2 chemistry.