<p>Micronuclei (MN) are tiny, membrane-bound DNA-containing compartments that are isolated from the primary nucleus. MN develops when a chromosome or fragment is not absorbed into the daughter nuclei during cell division. MN are characterized by impaired DNA replication, DNA repair defect, compromised nuclear envelope integrity, and altered nucleocytoplasmic transport. MN are markers of mutagenesis, genomic rearrangements, and chromosomal instability. The causes of MN include fragmented or lagging chromosomes not reincorporated into the primary nucleus. MN are typically a sign of genotoxic events and compromised integrity of the micronuclear envelope, which disrupts DNA replication, inhibits DNA repair, and exposes micronuclear DNA directly to the cytoplasm. Clastogenesis and aneugenesis processes actively contribute to MN formation and cellular transformation. Chromosomal rearrangements and accumulation of genetic mutations facilitated by MN are important factors in cellular transformation leading to development of disorders. MN formation can accelerate tumor growth via clonal evolution stimulation that triggers inflammatory pathways. Cell viability and cell cycle progression are significantly impacted by MN. The presence of MN disrupts the normal control of the cell cycle, resulting in genomic instability, prolonged cell cycle arrest, and delayed mitosis. Additionally, MN decrease overall cell viability by inducing apoptosis, mitotic catastrophe, and senescence pathways that lead to cell death. The fate of cells containing MN is further influenced by the cellular response, which includes the activation of autophagy, inflammatory pathways, and immunological responses. However, protocol standardization and technological advancements in MN research is needed to enhance its potential and uniformity, particularly through improved imaging and automation screening systems.</p> Graphical abstract <p></p>