Fig. 4

Association of higher expression of MTHFD2 with worse prognosis and malignant status of lung cancer. a Kaplan–Meier survival curves of patients in the NCC cohort. Red and blue lines depict survival curves of patients with cancer tissues with high and low levels of MTHFD2 mRNA, respectively. The cutoff value was determined as the median value of the expression levels of MTHFD2 mRNA. The p-values were calculated with a log-rank test. b Box-whisker plot of MTHFD2 mRNA for patients in different stages (edges of boxes represent the 25th and 75th percentiles and bold lines in boxes represent the median value). Whiskers were elongated to the largest and smallest values, which are not outliers. c Immunohistochemistry for MTHFD2 in normal and lung cancer tissues. Scale bar, 100 µm. d Comparison of MTHFD2 expression levels among lung cancer tissues that show different differentiation grades on the tissue microarray. Blue circles indicate scores of each patient. Statistical significance is calculated with Steel–Dwass method. N.S. not significant; *p < 0.05; **p < 0.01