Atxn1l, also known as ataxin 1-like, is a protein-coding gene. It is involved in multiple biological processes. It interacts with CIC (capicua) to form a transcription repressor complex, and this complex plays a role in modulating the sensitivity to MAPK pathway inhibition [1,3,4]. It is also related to the Notch-driven marginal zone B cell development and sepsis progression [2].

In loss-of-function studies, ATXN1L deletion reduces CIC protein, which in turn modulates sensitivity to the MEK1/2 inhibitor trametinib in cancer cells [1]. In B cell-specific Atxn1l-deficient (Atxn1lf/f;Cd19-Cre) mice, Notch signaling is disrupted in marginal zone B cells, leading to inhibited MZB cell development due to ETV4 de-repression and subsequent inhibition of Notch1 and Notch2 transcription. Also, in these mice, humoral immune responses and lipopolysaccharide-induced sepsis progression are attenuated but restored upon Etv4-deletion [2].

In conclusion, Atxn1l is essential for the regulation of multiple biological processes, especially through its interaction with CIC. The Atxn1l-deficient mouse models have revealed its significance in cancer drug sensitivity, B cell development, and sepsis progression, providing valuable insights into the underlying mechanisms of these biological processes and disease conditions.