(A-F) Flow cytometric analysis of K562 cells expressing ZsGreen or U21-ZsGreen labeled with antibodies to (A) ULBP1 (m295), (B) ULBP2, (C) ULBP3, (D) MICA, and (E) MICB (m360), or (F) ICAM-1 followed by a PE-conjugated secondary antibody. Cells labeled with secondary antibody alone are indicated by the filled dark gray trace. Control ZsGreen-expressing cells are indicated by the filled light gray trace, and ZsGreen-U21 cells are indicated by the black trace. (G-I) Cells were fixed, permeabilized, and labeled with antibodies directed against (G) MICA, (H) MICB (m360), or (I) TfR. Cells labeled with secondary antibody alone are indicated by the filled dark gray trace. Control ZsGreen-expressing cells are indicated by the filled light gray trace, and ZsGreen-U21 cells are indicated by the black trace.