To gain further insights into the mechanism of UCHL1 that is responsible for the progression of t(4;14) cytogenetic high-risk MM, we performed in vitro pharmacological targeting of UCHL1 in high-risk with t(4;14) (KMS11) and non-t(4;14) (KMM1) cell lines using UCHL1 inhibitor (LDN-57444). Here, UCHL1 is linked to Miyoshi myopathy.