HDAC9 and diffuse large B-cell lymphoma: Fimepinostat gained in 2018 Fast Track designation bythe FDA in adult patients with relapsed or refractory diffuse largeB-cell lymphoma (DLBCL) after two or more lines of systemic therapy,however it has not yet been finally approved. Indeed, hydrazides might offer significant advantages in this context,as their physicochemical properties and flexibility facilitate theincorporation of functional groups to address additional therapeutictargets without compromising the HDAC-binding efficiency.