ERBB2 and neoplasm: Of 333 HER2 double-equivocal cases analyzed by reflex FISH testing (22 HER2 double-equivocal cases failed to be tested because no additional blocks were available) using another FFPE block from the same tumor, 19 (5.7%, 19/333) positive, 75 (22.5%, 75/333) negative, and 239 (71.8%, 239/333) equivocation of HER2 status were found (Fig. 1).