Context: CREATE TABLE table_26957063_3 (_percentage_identity_to_c7orf38 INTEGER, genus_ VARCHAR, _species VARCHAR)
Question: What is the % identity to C7orf38 of the animal whose genus & species is Mus Musculus?
Answer: SELECT MAX(_percentage_identity_to_c7orf38) FROM table_26957063_3 WHERE genus_ & _species = "Mus musculus"