ELANE and chronic myelogenous leukemia, BCR-ABL1 positive: However, absolute quantification of the differences in ELA2 transcript levels between THP-1 (ELA2+) and RPM1 (ELA2-) cell lines showed that these differed by a factor of 20,000-fold (data not shown), whereas the magnitude of average differences between the normal and CML cells was only 50-fold.