In light of the high competition between researchers in the biomedical field, there is an increasing tendency to fill positions with younger scientists, and many positions are only available until the age of 35. Therefore, CCHD students should be graduated well before reaching that age in order to give them the opportunity to earn some postdoctoral experience when turning 35. Accordingly, applicants aged above 30 are generally not considered. However, this cannot be an absolute requirement, since a loss of time due to, for instance, maternity leaves or civil services, also needs to be considered. In any case, applicants who, at the time of the advertisement, have been working in one of the participating laboratories as doctoral student for already more than 6 months will not be entitled to apply for CCHD student positions.