STK39 and cancer: Paralog redundancy has been identified in CCNL1-CCNL2, OXSR1-STK39, EIF1-EIF1B, G3BP1-G3BP2, GFPT1-GFPT2, and PDS5A-PDS5B (190), MAP2K1-MAP2K2, RAS-RAF, FAM50A-FAM50B (192), sex chromosome genes ZFX-ZFY, DDX3X-DDX3Y, EIF1AX-EIF1AY (159), SAR1A–SAR1B, RAB1A–RAB1B, LDHA–LDHB, RBM26–RBM27 and hnRNPF–hnRNPH3 gene pairs (194) Recently, it was reported that VRK1 is a SL target in VRK2-mutated or silenced cancers (195, 196) and SMARCA2 is a SL target in SMARCA4 mutated cancers (197), suggesting SL is an excellent approach for paralog-related cancer treatment.