Fig. 1

Pyknon loci expression in CRC samples by qRT-PCR. a Expression and distribution of pyknon-containing regions were analyzed between CRC and paired normal samples (first set, see Additional file 4: Table S3) by qRT-PCR. b Expression and distribution of pyknon-regions were analyzed between MSS and MSI-H CRC by qRT-PCR. The number of samples with measurable expression values (under Ct of 35) is presented in parentheses. The numbers of cancer and normal samples in some cases differ from one another because patients with no expression values for the U6 or for pyknon regions were excluded. Two-sided t-test was used to evaluate differences between two groups. Y-axis values represent ratio of each pyknon region to U6: ratios were calculated with the 2^–ΔCt method using U6 levels for normalization. c, d Kaplan–Meier curves reveal a poor clinical prognosis for patients with high pyk-reg-90 expression in both cohorts (the first set had n = 114 and the second set n = 170 patients); the association was statistically significant with p = 0.016 and p = 0.013 for each set, respectively (log-rank test). The high/low pyk-reg-90 expression was determined according to a cutoff value corresponding to the mean value of all patients