hsa-mir-449b: Hsa-mir-449b is a microRNA that has been found to be differentially expressed between stage I and stage III cases [PMC9264529]. It is structurally similar to hsa-miR-34b*, hsa-miR-34b, hsa-miR-34c-5p, and hsa-miR-449a, which are downregulated in the testes of infertile men [PMC5399401]. The expression of hsa-mir-449b was detected using Taqman Universal MMIX II and Taqman probes [PMC6663943]. It has been shown that hsa-mir-449b can reduce the luciferase activity of certain reporter vectors when transfected with specific miRNA mimics [PMC6396440]. Hsa-mir-449b is one of the miRNAs that were analyzed in a study investigating miRNA expression profiles following carbon ion radiation exposure in mouse testis [PMC6024298]. Hsa-mir-449b is also associated with breast cancer, as it has predicted target genes that are breast cancer-associated genes [PMC5357838]. In male infertility, the expression of hsa-mir-449b has been found to be significantly downregulated in oligoasthenoterathospermia cases compared to other infertility groups and control group [PMC7851476]. The expression of hsa-mir-449b is negatively correlated with sperm progressive motility, sperm count, and normal morphology [PMC7851476]. Hsa-mir-449b is also part of gene modules constructed using the MCODE algorithm in a study investigating gene networks associated with cancer progression [PMC7339803]. Additionally, a variant in hsa-mir-449b has been identified at position 27 of the 5' arm and affects its secondary structure [PMC6863982].