Igniter Replacement but now No Gas

I just purchased and replaced lower oven igniter WB2X9154 after noticing boiler igniter still worked and gas lit but lower igniter did not glow. Now that I replaced lower it does glow but gas does not come on. Strange that upper boiler gas stopped coming on after repair. Could the gas valve have failed along with the lower igniter? Is it worth trying to replace more parts on this old oven if so which parts are most likely bad?