回复：各位老师求助（pijiang,xiao bai tu 或其他高人）：雇主能在多长的期限内撤对你的销绿卡申请？

ER has no power to revoke your GC petition (I-140). After you enter AC21 protection, your I-485 application is out of the reach of ER if there was no fraud.

But USCIS always has the power to revoke I-140, rescind the green card or denaturize your citizenship