Jill Larsen (The Prince Charles Hospital, Brisbane, Australia) and her colleagues have used gene chips developed from the Human Genome Project to study lung cancers that directly invade neighbouring lymph glands compared with those that spread to these lymph glands via the lymph drainage system. Different expression patterns were found on the gene chips that could predict how lung cancer cells leave the main tumour growth and involve lymph glands, whose role is to slow down the progress of cancers and infections.