PCM1, also known as pericentriolar material-1, is a protein that has multiple functions. It is a molecular marker of centriolar satellites, membrane-less organelles involved in numerous cellular and organismal processes [5]. In vertebrate radial glia progenitors, PCM1, asymmetrically distributed at the centrosomes, regulates polarized endosome dynamics and cell fate, facilitating endosome marker exchange and the formation of macromolecular complexes [3].

PCM1-JAK2 fusion is associated with various hematolymphoid neoplasms. In cases of myeloproliferative neoplasms, this fusion shows morphological similarities such as myeloproliferation, eosinophilia, and myelofibrosis, and clinical similarities like a striking male predominance and an aggressive course [4]. Patients with PCM1-JAK2 fusion-related neoplasia, including myeloproliferative neoplasms, acute leukemia, and T-cell cutaneous lymphoma, have different survival rates at 5-year follow-up. Recommended treatments include JAK2 inhibitors and hematologic stem cell transplantation, but the efficacy is limited by the small number of patients studied [2]. In a case of an atypical form of mycosis fungoides, the patient carried the isolated PCM1::JAK2 fusion and eosinophilia, with the disease being refractory to common treatments and demonstrating abnormal activation of the JAK-STAT pathway [1].

In conclusion, PCM1 has crucial functions in cellular processes such as regulating endosome dynamics and cell fate. The study of PCM1-JAK2 fusion in hematolymphoid neoplasms provides insights into disease mechanisms and potential treatment strategies, highlighting the importance of understanding PCM1-related genetic alterations in these diseases.