ACTB and central nervous system cancer: In addition, PD-L1 expression was significantly positively correlated with PI3K (p = 0, Figure 2F), SQSTM1 (p62, a negative marker of autophagic influx signaling) (32) (p = 0, Figure 2G) and ACTB (β-actin) (p = 0, Figure 2H) in human glioma tissues.