After an hour of deliberation Friday and four weeks of trial, a Philadelphia jury will continue its work today in a lawsuit over whether drugmaker Wyeth’s hormonal drug caused an Alabama plaintiff’s breast cancer.

The verdict in Singleton v. Wyeth will either continue or disrupt the run of jury verdicts in favor of plaintiffs in Philadelphia hormone-replacement therapy cases. There are 1,500 HRT mass tort cases pending in Philadelphia Common Pleas Court.