H-scores for immunohistochemical staining of protein markers in high-grade tumors. In the box plot, the diamond represents the mean, the upper and the lower bounds of the box represent the 75th and 25th percentiles, respectively, and the whiskers represent 90% confidence interval for the mean. Ig: Immunoglobulin; N: number of slides containing tumor specimens, each derived from a patient; PODXL: podocalyxin.