Clinical relevance of genomic copy number variation in PRL-PAs. (A) Immunohistochemistry of BCAT1, MYC, Ki-67, PRL, and PIT1 in high and low CNV PRL-PAs. ×100 magnification, the scale bar = 100 μm. (B) Prolactin expression levels (TPM) in PRL-PAs with high CNV, PRL-PAs with low CNV, GH-PAs and NFPAs. *P<0.05, **P<0.01, ***P<0.001 (C) Copy number and expression level (TPM) of BCAT1 in different PA subtypes. Both copy number and expression level of BCAT1 were increased in PRL-PAs. (D) PRL-PA patients in the high CNV group more frequently developed drug resistance. The yellow bar indicates the number of patients that are sensitive to BCT treatment, while the blue bar indicates number of patients that are insensitive to the same treatment. P value = 0.026, Chi-Square test. (E) High CNV group in PRL-PAs exhibits a higher degree of malignancy. The PA malignancy was defined by the number of positive Ki-67 foci in IHC. P value = 0.059, Chi-Square test. (F) The Scatter plot shows positive correlation (spearman correlation coefficient: 0.47) of transcriptomic alterations in high CNV group relative to low CNV group (x-axis) and relapsed PAs relative to un-relapsed PAs (y-axis).