Combination of different antibodies
If they are made in different animals you should be fine.  You could do a western with those antibodies though, to double-check.  Looks like Cenp-C is about 106kD and Rod1 is about 60kD.  So on a western, if you see bands at both those sizes with one of the antibodies, you have cross-reactivity between those proteins.  And if you just see the specific band you're looking for, you're good.