STK11 and breast cancer: Fifty-eight percent (7 cases) of breast carcinomas with low HMW-CK expressions showed weak staining for LKB1, and 64% (7 cases) negative HMW-CK samples showed negtive or weak staining for LKB1, as compared to 38% (6 cases) of the high HMW-CK expression cases (Figure 1I and J) (Figure 2D), indicating that LKB1 expression level was positively correlated with the expression level of HMW-CK in clinical breast cancer tissues (Figure 1I and J) (Figure 2D).