has part has part has_part characteristic of has modifier osteoblast abnormal osteoblast cell number decreased osteoblast cell number MP:0000058 MPheno.ontology reduction in the number of skeletogenic cells that secrete osteoid, are capable of producing mineralized (hydroxyapatite) matrix, are located adjacent to or within osteoid tissue, and arise from the transformation of a preosteoblast cell decreased osteoblast formation reduced osteoblast formation reduced osteoblast cell number MP:0004989 abnormal decreased amount