So, um, so the fact of the matter is that I’ve often encouraged people in my laboratory to come up with their own ideas to work on interesting questions. Every year or two there’s some dramatic new technique which turns out to be very useful in understanding one problem or another and when people come to my lab I ask them what they’d like to work on and they say ‘Well, I want to use this technique to study this problem.’ And I ask them ‘Why do you want to study this problem’ and he said or they would say ‘Look at all the data that I could obtain. ‘And I say ‘Why do you want to generate all that data?’ They say ‘Well look at what one could learn from this.’ I say ‘Well what could one really learn from this? What is the biological question that is motivating your interest?’ And they step back and mumble a few words and then they disappear for some days and come back with a better formulation – often realizing that they were very enamored by the technique like gene cloning or DNA sequencing without having any clear understanding or insight into the underlying, motivating biological question. Well, to my mind, to be a good mentor – one needs to work in several different ways. First of all, one has to embolden young people to think independently and not to believe everything that their mentor is telling them. Healthy skepticism is always good. People who always agree with me are people who do not gain my respect. The other thing which is a little more subtle and more challenging is to develop a taste for scientifically interesting questions. What do we really want to know conceptually rather than how much data do we want to accumulate. And there’s lots of data collection that one can do now. These days a student can gather information on the sequence or the structure of the gene at a rate that is maybe ten thousand times higher than when I was a graduate student. So I think there are several attributes of a good mentor: one is to encourage independence thinking of one’s trainees. If students are intimidated by the mentor – if they don’t think on their own, then sooner or later they will sink in their own independent careers rather than swim and so people in my group have always been encouraged to think independently and to disagree with me. To understand that I don’t really respect people who never disagree with me because it suggests to me that they don’t have anything going on inside their own brain. But far more challenging to my mind is the following question: how can a young person learn to distinguish or to differentiate between questions that are worth answering and are interesting and those that simply involve the massive accumulation of data without there being any clear justification. Why do you want to do this experiment? What’s the possibly interesting outcome? Are you just interested in going on a fishing expedition as it’s sometimes called? Or a wool gathering expedition where you gather all kinds of data without having any likelihood or pretense of being able to solve an interesting problem. So this taste for developing a focus on interesting problems really is to my mind, among the most challenging for young people.

Robert "Bob" Weinberg is Daniel K. Ludwig Professor for Cancer Research and director of the Ludwig Cancer Center at MIT, an American Cancer Society Research Professor, and is a founding member of the Whitehead Institute for Biomedical Research.

In 1982 he was one of the scientists to discover the first human oncogene, Ras, which causes normal cells to form tumors, and his lab also isolated the first known tumor suppressor gene, Rb.

He co-authored with Douglas Hanahan the landmark "Hallmarks of Cancer" paper in 2000, which laid out the six requirements for a healthy cell to become cancerous.