ATRX and cancer: These genes were chosen because (1) they are robustly detected by RNA FISH; (2) they are “cancer-specific” escapees in some tumor cell lines (except ATRX and MAGEA6); and (3) HDAC8 and ATRX lie in proximity to each other and to XIST (within a few megabases), thus minimizing their chances of being separated by translocations and facilitating RNA FISH analysis in tumors.