Table 1. Antibody sources, manufacturers, clones, dilutions, incubation times, and antigen retrieval methods.

Antibody	Antibody source	Clone	Diluition	Incubation time	Antigenal retrieval
CD4	Sino Biological®	M22	1:50	30 minutes	HIER, citrate pH 6
FAS-L	Arigo®	Policlonal	1:50	16 hours	HIER, citrate pH 6
Granzyme B	Arigo®	Policlonal	Ready to use	1 hour	HIER, citrate pH 6
Perforin	Arigo®	DG9	1:100	1 hour	Enzymatic Pepsin

HIER = heat-induced epitope retrieval. Previously tested mammary gland samples were used as positive controls; negative controls were obtained by replacement of the primary antibody by IgG. Detection system used was NovoLink detection system (Leica Biosystems, Buffalo Grove, IL).