13. ADDITIONAL EXCLUSION CRITERIA FOR PATIENTS IN COHORT 1 (vemurafenib+cobimetinib+atezolizumab): Cardiac Exclusion Criteria: History of clinically significant cardiac dysfunction, including the following: a. Unstable arrhythmia b.History of congenital long QT syndrome c.Mean (average of triplicate measurements) QTc interval corrected using Fridericia's method >/= 450 ms at screening, or uncorrectable abnormalities in serum electrolytes (sodium, potassium, calcium, magnesium, and phosphorus)