Morphology of SHEE cell (photographs of phase con-trast microscope). A, SHEE10, good differentiation (× 400); B, SHEE31, differentiated to two directions, well differentiated (left), and poorly differentiated (right) (× 200); C, SHEE60, poor differentiation (× 400); D, SHEE85 shows different shape and size with larger nucleolus (× 400)