Mentoring during training and the early career is one possible means of cultivating virtue in the practice of science. To examine its perceived impact, we approached virtue and its cultivation using a conceptual framework compatible with virtue ethics: the systems model of good work. We discuss two studies which show that many leading scientists report a wide range of ethical responsibilities and that scientists mentored by moral exemplars absorb ethical commitments from their mentors. A third study found that early-career scientists' assimilation of scientific virtues diverged in focus and scope from exemplars' mentees. These findings expand our perspective on, and raise questions about, mentoring for virtue in the sciences today. We discuss conceptual implications of the systems model of good work for the cultivation and practice of scientific virtues and show how the model can help frame questions and generate hypotheses related to virtue in science.