YAP1 and AL amyloidosis: The important role of PTEN‐induced putative kinase 1 (PINK1)‐dependent mitophagy in regulating multiple myeloma progression and its effects on the Mps one binder kinase activator (MOB1B) Hippo‐Yes‐associated protein (YAP)/transcriptional co‐activator with PDZ‐binding motif (TAZ) pathway are summarized, with an emphasis on myeloma cell homing and migration.