DDX3X and neoplasm: As expected, knockdown of DDX3X impaired TNBC cell proliferation (Supplementary Fig. S3G–S3L), migration, and invasion (Supplementary Fig. S3M–S3P), suggesting that DDX3X is an oncoprotein and KLHL29 might exert its tumor suppressive functions by inhibiting DDX3X, which is further investigated below.