Model for the mechanism of PATRR-mediated translocation. (a) The PATRR might be cleaved at the tip of the hairpin structure, which corresponds to the center of the palindrome (“center-break mechanism”). (b) Alternatively, the PATRR might be cleaved diagonally at the base of the cruciform (“kesa-giri” refers to the way a Japanese samurai kills an enemy with his sword). Two PATRRs, located on different chromosomes, are indicated by red and blue lines, respectively.