METTL8 expression in public dataset. (A) A list of 10 genes with significantly up-regulated expression in canine mammary tumor among 400 methyltransferases. Expression level of genes are represented as log2 (TPM+1). (B) METTL8 mRNA sequence and protein similarity between human and canine. (C,D) Boxplot showing relative expression of METTL8 in canine mammary tumor (C) and in breast cancer (D). (E) Boxplot showing relative expression of METTL8 in breast cancer subtype. (F) METTL8 transcript levels. Total RNA extracted from MCF-10A, MDA-MB-231, MDA-MB-453 and SKBR3 cells lines and subjected to RT-qPCR analysis for METTL8. * indicates p < 0.05, ** p < 0.01, and *** p < 0.001, CMT: canine mammary tumor, HBC: human breast cancer.