Figure 2.

Histological classification of mammographic density. Haematoxylin and eosin-stained breast tissue was assessed by a panel of scientists to grade mammographic density according to the percentage area occupied by fibroglandular tissue. A density score of 1 is 0–10% (A), score of 2 is 11–25% (B), score of 3 is 26–50% (C), score of 4 is 51–75% (D) and score of 5 is greater than 75% fibroglandular tissue (E). These density scores were then used to select patient fibroblasts to be used in cell culture studies.