Pluripotent state–specific transcription factor (Oct-4, NANOG, and REX-1) expression. (A) Human heart-derived (hH1 and hH2), liver-derived (hL1 and hL2) and bone marrow–derived (hBM1 and hBM2) cells express, at mRNA level, at least 2 of the tested markers. Green dots (A488; B), and white dots (A488; C) represent the nuclear expression of oct-4 and nanog proteins, respectively. Nuclei are depicted by the blue fluorescence of DAPI staining. Image acquisition was carried out by a Confocal Laser Microscope (Leica TCS-SP2; Leica Microsystems, Milano, Italy), using a 63 × oil immersion objective (numeric aperture: 1.40). Adobe Photoshop software was used to combine RGB channels, overlay the images, and adjust contrast (Adobe, San Jose, CA).