Immunohistochemical analysis of tumor antigens expression and T cell infiltration. (A) Hematoxylin and eosin (H&E), Melan-A/MART-1 and HMB-45/gp100 stainings in pre- (November 2011) and post- (April 2012) sunitinib tumor lesions. (B) Analysis of infiltrating immune T cells (CD3 and CD8) in sunitinib-treated tumor. Higher magnification in a shows area of pathologic tumor regression associated with lymphocyte infiltration; Bottom panels show CD3 and CD8 stainings; square b reports the high magnification of area infiltrated by CD8+ T cells. All scale bars indicate 50 μm.