Marcus Caerellius Hieronimus was member, in 198, of the collegium of the fabri tignuariorum Ostiensium (CIL XIV 4569). He was also pater (CIMRM 282, CIL XIV 70) as it is said a small white marble base discovered in 1867 in the area of the sanctuary of Magna Mater.
The Caerelli people seem to have played, in the 2nd-3rd centuries, an important role in the college of pistores in Rome and Ostia. In Rome we know a M. Caerellius Zmaragdus, curator pistorum in 144 (CIL VI 1002 = 31222) and in Ostia a M. Caerellius Iazemis, quinquennalis pistorum III et perp(etuus), et codicarius, item mercator frumentarius (CIL XIV 4234).
—Bricault et Roy 2021.
Other brothers from Ostia
This marble slab found near the Casa de Diana in Ostia bears two inscription with several names of brothers of a same community
[M. Lollia]no Callinico / [patre Pe]tronius Felix / [Marsus sign]um deo / [donum] ded(it) / . . . atus xinu . . . / fecit.
M. M. Caer[ellius Hiero]/nimus et C[allinic]/us sacerdo[tes et antisti]/es Solis [invic(ti) Mithrae] / thronum / fec(erunt).
Marcus Lollianus Callinicus being [Pater, Quintus Pe]tronius Felix [Marsus] offered [as a gift] the image of the god and dedicated it [---atus, at his own expense?] did.
Marcus Caerellius Hieronimus and Marcus Caerellius Callinicus, priests and antistes of Sol invincible Mithras, made the throne.