CYP2C19 and breast cancer: Discordant Coverage Policies. Of the tests reviewed by more than one insurer, five tests had discordant coverage policies: the Allomap test for cardiac allograft rejection risk, the Mammaprint test for breast cancer risk recurrence, CYP2C19 testing for use of clopidogrel, and EGFR and KRAS testing for erlotinib.