NAE-IN-M22 (NEDD8 inhibitor M22) is a selective, potent and reversible inhibitor of NEDD8 activating enzyme (NAE). NAE-IN-M22 inhibits multiple cancer cell lines and induces apoptosis in A549 cells. NAE-IN-M22 also can inhibit tumor growth in vivo.

NAcM-OPT is a specific, reversible inhibitor targeting N-Acetyl-UBE2M interaction with DCN1 （IC50: 79 nM).

PYZD-4409 is a selective UBA1 inhibitor with an IC50 of 20 μM. PYZD-4409 induces cell death in malignant cells and is preferentially cytotoxic to malignant cells over normal hematopoietic cells.

RITA (NSC-652287)(NSC-652287) induced cross-links of both DNA-DNA and DNA-protein with no detectable DNA single-strand breaks. RITA, like nutlin-3, can disrupt the p53/Mdm2 interaction.

Nutlin-3 is an MDM2 antagonist that inhibits MDM2-p53 interaction (Ki=90 nM) and activates p53. Nutlin-3 binds preferentially to the p53-binding pocket of MDM2, leading to stabilization of p53 and activation of the p53 pathway. Nutlin-3 has antitumor activity.

Idasanutlin (Ro 5503781) (RG-7388) is an effective and specific p53-MDM2 inhibitor (IC50: 6 nM).

NSC-697923 (2-[(4-methylphenyl)sulfonyl]-5-nitrofuran), a potent inhibitor of UBE2N (ubiquitin-conjugating enzyme E2 N, Ubc13), exhibits its role in inducing cell death in neuroblastoma (NB) cells through two distinct mechanisms. In p53 wild-type NB cells, NSC-697923 promotes the nuclear importation of p53, thereby triggering cell death. Meanwhile, in p53 mutant NB cells, NSC-697923 activates the JNK-mediated apoptotic pathway, leading to cell death. Additionally, NSC-697923 inhibits DNA damage and NF-κB signaling, further contributing to its antitumor activity.

PYR-41 is the first cell-permeable inhibitor of ubiquitin-activating enzyme E1, with no activity at E2.