Informal admission email

Hi, I just received an email saying that the admissions committee has selected me for admissions to a Mol/Cell Bio PhD program, but that admission is contingent on admission to the graduate school, whose decision is still pending. Just wondering what to make of that? I had a sub 3.0 undergrad gpa that I managed to make up for with research experience and letters so I’m a little nervous that this could still go wrong. Thanks and good luck to everyone on here who’s waiting, good things are coming for all of us!