Examples of positive staining of tumoral tissue sections. A) Invasive ductal carcinoma, patient L116. Hematoxylin-eosin stain in 200× magnification reveals poor differentiation with a predominantly solid infiltrative pattern. The nuclei are highly pleomorphic with notable nucleoli. B) Outgrowths of cells from tumor fragment in vitro phase contrast (400× magnified). C) Immunostaining for ER, patient L116 (100× magnified). D) Immunostaining for PR, patient L116 (100× magnified). E) Immunostaining for HER 2/neu, patient L116 (400× magnified). F) Immunostaining for Ki67 with MIB-1 antibody, patient L122 (400× magnified).