N.J. Stat. Ann. § 18A:66-60

Except as otherwise herein provided, no trustee and no employee of the board of trustees shall have any direct interest in the gains or profits of any investments of the retirement system; nor shall any trustee or employee of the board directly or indirectly, for himself or as an agent, in any manner use the moneys of the retirement system, except to make such current and necessary payments as are authorized by the board of trustees; nor shall any trustee or employee of the board of trustees become an endorser or surety, or in any manner an obligor for moneys loaned to or borrowed from the retirement system.