Enables methylated histone binding activity. Involved in several processes, including negative regulation of transcription by RNA polymerase II; positive regulation of histone H3-K27 methylation; and stem cell population maintenance. Part of ESC/E(Z) complex. Is expressed in brain ventricular layer; early conceptus; eye; genitourinary system; and intestine. Orthologous to human PHF19 (PHD finger protein 19). [provided by Alliance of Genome Resources, Apr 2022]