The molecular modelling of larger proteins benefits from a preliminary analysis of the sequence to identify regions of potential structural and functional importance. In this study the sequence of the epidermal growth factor receptor has been analysed using a variety of established methods and novel procedures developed for the study of weak internal and external homologies and for the use of homologous sequences in the prediction of secondary and super-secondary structures. The procedures explored here are potentially suitable for incorporation into an expert system for the initial investigation of protein sequence data.