An occasional column, in which Caveman and other troglodytes involved in cell science emerge to share their views on various aspects of life-science research. Messages for Caveman and other contributors can be left at caveman@biologists.com. Any correspondence may be published in forthcoming issues. Previous Sticky Wickets can be viewed at: www.biologists.com/JCS/caveman/index.html How do you define a leader for your field? I'll bet money that your definition starts with the person who publishes the most influential papers that propel the field forward. You may also correlate leadership with big talks at big meetings, prizes, and membership of editorial boards and review panels. In other words, the leader is identified by his/her individual scientific contribution to the field. That's nice, but it doesn't answer my question. Maybe you missed its subtlety? I asked for the definition of a leader for your field not in your field. Let's start again. How would you define a leader for your field? Still mystified? OK, these are my answers. A leader for a field synthesizes ideas from all contributors and is generous in airing the views of others in the field even if they are contrary to his/her own work. A leader for a field is openly and constructively critical of published studies and the direction of the field. A leader for a field seeks to promote discussion of new ideas and approaches. A leader for a field encourages the involvement of scientists in other disciplines, with the overall goal of enriching and diversifying the field. A leader for a field is an advocate defending the field against unfair criticism, encouraging increased funding and prominence of the field at scientific meetings, and working to increase the overall visibility of the field to the scientific and non-scientific community. A leader for a field champions the field to politicians and administrators who make policy and control budgets. Of course, leadership in a field and leadership for a field are not necessarily mutually exclusive. I am sure you can name many who are widely identified as leaders because of their individual contributions to their field and have taken on prominent roles as leaders for their fields, particularly as advocates. I can also name many scientists who have taken the responsibility to be leaders for their field, although their science has not necessarily (always) made the headlines. However, there are also many leaders in their field who have remained quiet when called upon to take a stand or have avoided service for their field. The differences between these forms of leadership are not subtle. Leadership in a field requires the continual development of new ideas and approaches in one's laboratory, the recruitment of quality students, and the never ceasing quest for the spotlight to illuminate one's work in leading journals and at scientific meetings. Leadership for a field requires the altruism to promote the field as whole (rather than just from the context of one's own research), respect from one's colleagues so that one can represent the field honestly and broadly, the responsibility to help guide the direction of the field, and selflessness in promoting criticisms, self-evaluation and discussion within the field. Based on such a comparison, here is another way to think about these definitions of a leader. A leader in a field works to improve their standing as an individual in the community. A leader for a field works to improve the community as a whole. While a few may become leaders in their respective fields, all of us should strive to become leaders for our field, regardless of our perceived position in the hierarchy.