The MARS test that must be performed is the the Wisdom Panel PROFESSIONAL
Unrivaled Dog Breed Detection & Accuracy - Wisdom Panel Professional which is a blood draw NOT the cheek swab test. The cheek swab test does not compare the same markers as the blood test. The cheek swab test will have some odd results however the blood draw test is quite accurate. While many people say they have not used it or they have a friend who did etc., I can say I personally have tried it on Biewers as well as mixes to test the accuracy for my own knowledge and it was 100% spot on for each of the tests I performed.