Section 922(q) at time of Lopez:

It shall be unlawful for any individual knowingly to possess a firearm at a place that the individual knows, or has reasonable cause to believe, is a school zone.

Section 922(q) as amended after Lopez:

It shall be unlawful for any individual knowingly to possess a firearm that has moved in or that otherwise affects interstate commerce at a place that the individual knows, or has reasonable cause to believe, is a school zone.