['Carbohydrate antigen 15-3 (CA15-3), Kerbs von den Lungen (KL-6) and breast cancer antigen 225 (BCA225) are widely used tumor markers for breast and lung cancer respectively.', 'We analyzed 460 Japanese volunteers for 99 items on blood examination including 27 serum tumor markers. Correlations between 27 tumor markers and the other items were statistically analyzed.', 'Positive correlations were identified between CA15-3 vs. KL-6, CA15-3 vs. BCA225, and KL-6 vs. BCA225, with correlation coefficients of 0.84, 0.86, and 0.79, respectively.'] Are serum levels of CA15-3 , KL-6 and BCA225 positively correlated with each other in the general population?