Given an abstract, indicate which of the provided candidate titles (Option1 and Option2) best describes it (respond with the text of the title, not option1/2).

Example Input: Abstract: The regulation of alkaline phosphatase activity by steroid hormones was studied in two human breast cancer cell lines, MDA-MB-157 and BT20. MDA-MB-157 cells were shown to express the alkaline phosphatase isoenzyme produced by normal breast tissue, and the activity of this isoenzyme increased 3-fold after a 72-h treatment of these cells with 10(-7) M 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3], 2-fold after treatment with 10(-6) M hydrocortisone (HC), and 5-fold after treatment with both hormones. BT20 cells did not express the isoenzyme phenotypic to breast, but ectopically expressed the isoenzyme phenotypic to term placenta and other embryonic tissue. Treatment of BT20 cells with 1,25-(OH)2D3 results in a 30% decrease in alkaline phosphatase activity of the embryonic isoenzyme. There was a 2-fold increase in activity after treatment with HC, and enzyme activity was similar to control values after treatment with both hormones. For both cell lines, changes in alkaline phosphatase activity correlated with changes in nanograms of isoenzyme per mg cellular protein, as measured by RIA. Increases in enzyme activity were inhibited when the cells were incubated simultaneously with the steroids and cycloheximide. Studies with receptors in each cell line showed that both cell lines bound 1,25-(OH)2D3 and that a 1,25-(OH)2D3-binding protein with the same mol wt as the D3 receptor was present in both. The BT20 cells also express a larger mol wt protein which binds 1,25-(OH)2D3 but is not as specific for the 1,25-(OH)2D3 isomer. HC receptors were similar in quantity and binding affinity in both cell lines.
Which is the apt title for the abstract? option1: 1,25-Dihydroxyvitamin D3 exerts opposite effects on the regulation of human embryonic and nonembryonic alkaline phosphatase isoenzymes. option2: Granulocyte-macrophage progenitor cells in term and preterm neonates.
Example Output: 1,25-Dihydroxyvitamin D3 exerts opposite effects on the regulation of human embryonic and nonembryonic alkaline phosphatase isoenzymes.

Example Input: Abstract: I have suggested that the X-linked gene Tabby (Ta) and its autosomal mimics in the mouse may be homologous with the genes for sex-linked anhidrotic (hypohidrotic) ectodermal dysplasia (Christ-Siemens-Touraine syndrome, CST) and its apparent autosomal mimics in the human. In the present study, I examined whether anhidrosis, a cardinal feature of CST, is present in the putative mouse sex-linked model, Tabby. The results demonstrate that whereas normal mice perspire on the volar and plantar surfaces of their paws, hemizygous Ta/Y male mice show anhidrosis and absence of sweat glands, as do human hemizygous male sufferers of CST. This result is strongly supportive of the hypothesis that Ta is homologous to the gene for CST.
Which is the apt title for the abstract? option1: Anhidrosis and absence of sweat glands in mice hemizygous for the Tabby gene: supportive evidence for the hypothesis of homology between Tabby and human anhidrotic (hypohidrotic) ectodermal dysplasia (Christ-Siemens-Touraine syndrome). option2: Glucocorticoid receptors lacking hormone-binding activity are bound in nuclei of ATP-depleted cells.
Example Output: Anhidrosis and absence of sweat glands in mice hemizygous for the Tabby gene: supportive evidence for the hypothesis of homology between Tabby and human anhidrotic (hypohidrotic) ectodermal dysplasia (Christ-Siemens-Touraine syndrome).

Example Input: Abstract: As a means of providing defibrillation as soon as possible for those suffering out-of-hospital ventricular fibrillation, numerous communities have trained and authorized emergency medical technicians (EMTs) to provide defibrillatory shocks (EMT-D). The findings of four controlled studies and the experience of various communities have answered important questions. EMT-D programs have been shown effective in urban, suburban, and rural communities with and without paramedic backup. EMT-D programs appear safe, with errors of commission being extremely rare and errors of omission being of acceptably low incidence. Issues still to be resolved include the degree and amount of training that should be given and whether manual or automatic defibrillators should be used. Medical supervision and quality control is the most important aspect of EMT-D programs. At its core, the success of EMT-D programs is confirmation of the principle of early defibrillation. Wider dissemination of early defibrillation will improve survival from sudden cardiac death.
Which is the apt title for the abstract? option1: Defibrillation performed by the emergency medical technician. option2: Molecular mapping of murine I region recombinants. II. Crossing over in the E beta gene is restricted to a 4.5 kb stretch of DNA that excludes the beta 1 exon.
Example Output:
Defibrillation performed by the emergency medical technician.