Myc-tagged Cullin 1, Cullin 2, Cullin 3, Cullin 4A, Cullin 4B, Cullin 5, Flag-tagged SPOP WT, Y87C, F102C, W131G, delta MATH, delta BTB, pLenti-HA-SPOP WT, Y87C, F102C, W131G, pGEX-4T-1-SPOP, Flag-Keap1, Flag-Cop1, shScramble, shCullin 3, shSPOP, and His-ubiquitin constructs were described previously 31 (link). shAR, shERG, shTrim24, shDEK and sgSPOP constructs were described previously 31 (link), 32 (link). Myc-Cullin 7 construct was kindly offered by Dr. James A. DeCaprio (Dana-Farber Cancer Institute). KLHL2 and KLHL3 constructs were generous gifts from Dr. Shinichi Uchida (Tokyo Medical and Dental University). KLHL12 and KLHL37 constructs were purchased from Addgene. KLHL20 construct was offered by Dr. Ruey-Hwa Chen (Institute of Biological Chemistry, Academia Sinica, Taiwan). The construct of HA-PD-L1 (HA tag in the N-terminus of PD-L1) was kindly provided by Dr. Mien-Chie Hung (The University of Texas MD Anderson Cancer Center). HA-Cdh1, HA-Cdc20, shCdh1, hCdc20 and HA-14-3-3 isoform constructs were described previously 33 (link), 34 (link). pCMV-CDK4 WT, pCMV-CDK4 N158F and shcyclin D3 were described previously 35 (link), 36 (link). pBabe-p16 was a kindly gift from Dr. Charles J. Sherr laboratory. pLKO-shCDK4 (Plasmid #78153 and #78154) and pMLP-shCDK6 (Plasmid #73552 and #73553) were purchased from Addgene. pLKO-sh14-3-3γ (TRCN0000078160, TRCN0000078161, TRCN0000078162), pLKO-shp16 (TRCN0000039748, TRCN0000039751, TRCN0000039782) and pLKO-shCD8a (TRCN0000057583, TRCN0000057587) were purchased from Open Biosystems. pcDNA3-PD-L1, pCMV-GST-PD-L1-tail (cytoplasmic amino acids), HA-PD-L1-ΔC-tail, HA-PD-L1-Δ283-290, HA-PD-L1-S283A, HA-PD-L1-S285A, HA-PD-L1-T290M, pLenti-PD-L1 WT, pLenti-PD-L1-Δ283-290, pLenti-PD-L1 T290M, pET-28a-His-SPOP WT, pET-28a-His-SPOP S6A, pET-28a-His-SPOP S22A, Flag-SPOP with delta D-Box (RxxL), pLenti-HA-c-Myc WT, pLenti-HA-c-Myc T58A/S62A, pLenti-HA-cyclin D1, pLenti-HA-cyclin D2, pLenti-HA-cyclin D3, Flag-SPOP S6A, HA-tagged CDK2, CDK4 and CDK6 were generated in this study.