MICALL1 (MICAL like 1) is a lipid-binding protein that functions as a Rab protein effector on endosomal membranes, orchestrating multiple aspects of membrane trafficking. Its primary role involves recruiting cytosolic proteins to regulate endosomal membrane tubulation and fission 1. MICALL1 specifically binds phosphatidic acid on recycling endosomes and coordinates early actin-driven fission steps with later nucleotide hydrolysis events by recruiting FCHSD2 and subsequently EHD1 1. The protein regulates receptor-mediated endocytosis, particularly EGFR trafficking, and facilitates slow endocytic recycling of cargo proteins back to the plasma membrane 2. MICALL1 also participates in ciliogenesis by recruiting EHD1 to primary cilia 3. Clinically, MICALL1 has emerged as disease-relevant in multiple contexts. It is a novel p53 target gene whose expression is suppressed in colorectal cancer tissues with p53 mutations, linking it to cancer development 4. MICALL1 shows significant association with Alzheimer's disease through aggregated rare variants in East Asian populations, with differential expression in AD brains 5. Additionally, elevated MICALL1 expression in hepatocellular carcinoma correlates with worse prognosis and increased immune cell infiltration 6, and genetic variants in MICALL1 show pleiotropy with luminal A breast cancer susceptibility and bioavailable testosterone levels 7.