bta-mir-133b: Bta-mir-133b is a miRNA that was found to be up-regulated in OECs from non-pregnant cows compared to pregnant cows [PMC7969882]. Along with bta-mir-133b, five other miRNAs (bta-miR-205, bta-miR-584, bta-miR-551a, bta-miR-1193, and bta-miR-1225-3p) were also up-regulated in OECs from non-pregnant cows [PMC7969882]. These miRNAs were found to be involved in the regulation of 37 selected pathways in OECs [PMC7969882]. Interestingly, the up-regulation of bta-mir-133b and other identified miRNAs in non-pregnant cows was also observed in previous studies that exposed bovine OECs to different hormone levels without the presence of an embryo [PMC7969882]. Additionally, a study using stem-loop RT-qPCR confirmed the differential expression patterns of nine out of 14 miRNAs identified by RNA-seq analysis, including bta-mir-133b [PMC4840452]. Furthermore, the expression of bta-mir-133b was found to be upregulated in an infected compartment compared to a control group [PMC4840452]. Overall, these findings suggest that bta-mir-133b plays a role in regulating gene expression and may be involved in reproductive processes and immune responses.