Disclosed are aryl pyrimidine compounds, as well as pharmaceutical compositions and methods of use thereof. One embodiment is a compound having the structure (I) and pharmaceutically acceptable salts, prodrugs and N-oxides thereof (and solvates and hydrates thereof), wherein A, Z, R and R′ are as described herein. In certain embodiments, a compound disclosed herein inhibits the activity of one or more members of the TGF-β superfamily, and can be used to treat disease by blocking such activity.