SPI1 and non-small cell lung carcinoma: However, when we calculated the median PU.1 expression level and grouped the NSCLC cohort based on the median value in a PU.1low and a PU.1high group, we found that the PU.1high group showed a significantly increased recurrence-free survival (RFS) and metastases-free survival (MFS) (Figure 4C). While approximately 47% in the PU.1low group were still metastases and recurrence-free 36 months after surgery, at the same time point, in the PU.1high group the proportion of metastases and recurrence free patients accounted for 80% (Figure 4D).