These cells were cloned from the GIRARDI HEART cell line (passage #623) in 1981 and were thought to "represent human heart cells"; however, isoenzyme analysis (Nelson-Rees et al., Science 191: 96-97, 1976) and DNA fingerprinting at the Creative Bioarray established unequivocally that this cell line must be considered de facto a subclone of HELA; cells were described to be sensitive to various toxins and hormones