Southern blotting analysis of the NK-YS genome for the rearrangement of the T-cell receptor (A) β and (B) γ chain genes. DNA extracted from human placenta was used as a negative control (NC). (A) BamHI- or EcoRI-digested DNA was electrophorased in the left or right lane, respectively. (B) EcoRI-,BamHI-, or HindIII-digested DNA was electrophorased in the left, center, or right lane, respectively. The NK-YS cells show the germ-line configuration of T-cell receptor β and γ chain genes.