Abstract
Direct chromosome analysis with G-banding revealed homogeneously staining regions (HSR) in five of 16 human solid malignant tumours of different histological types. The HSRs were localized either terminally or interstitially on the marker chromosomes. The great stability of the HSR-carrying markers in the tumour cells suggests an interrelationship of malignant cell proliferation with the HSR. In a single case the HSR showed a moderate staining intensity for C-heterochromatin.