This entry contains a number of protein families with apparently unrelated functions. These include the YAP binding proteins of yeasts. These are stress response and redox homeostasis proteins, induced by hydrogen peroxide or induced in response to alkylating agent methyl methanesulphonate (MMS). The family includes Aberrant root formation protein 4 (Alf4) of Arabidopsis thaliana (Mouse-ear cress), which is required for the initiation of lateral roots independent from auxin signalling. It may also function in maintaining the pericycle in the mitotically competent state needed for lateral root formation. The family includes glomulin (FAP68), which is essential for normal development of the vasculature and may represent a naturally occurring ligand of the immunophilins FKBP59 and FKBP12.