Schematic drawing of the GPIb-IX-V complex showing GP1bα, GPIbβ, GPIX, and GPV subunits that constitute the complex on platelet surface. Biallelic variants in GP1BA, GP1BB, and GP9 result in Bernard-Soulier syndrome. Monoallelic variants in GP1BA and GP1BB are associated with isolated macrothrombocytopenia. Figure reproduced with modifications from Luo et al²  with permission. P, phosphorylation sites. Professional illustration by Patrick Lane, ScEYEnce Studios.