“…THE AMOUNTS OF PROSTAGLANDINS extracted from various tumours, notably from human carcinomas of the breast (Bennett et al, 1975Powles et al, 1976), large intestine (Bennett et al, 1977) and kidney (Atkins et al, 1977) and from certain experimental neoplasms (Powles et al, 1 973;Tashjian et al, 1974;Galasko, 1.976;Galasko & Bennett, 1976) are usually greater than from the corresponding normal tissues. Prostaglandins and other lessclearly defined "tumour-associated" products may be involved in the establishment and growth of metastases in bone and possibly in other sites (Carter, 1978;Bennett, 1979).…”