KRT8 and chordoma: We first investigated the effect of Doxo (0.5 μM) and Irino (50 μM) on KRT8 expression of CM319 and UCH1 chordoma cells, and found that chemotherapy significantly promoted the expression of KRT8 in CM319 and UCH1 cells in a time-dependent manner, as shown by the quantitative reverse-transcriptase PCR (qRT-PCR) analysis (Fig. 1a).