Erg is an important downstream target involved in the effect Trib1 has on Hoxa9. (A) Immunoblotting showing an increase in 55-kDa Erg protein expression (arrow) in Trib1 hi cells. (B) Growth promotion of Trib1 null cells by Myc-tagged Erg overexpression. Immunoblotting of Myc-tagged Erg protein expression (left). Cell numbers of Trib1 null, Trib1 null with Erg, and Trib1 hi cells are shown on the right. (C) shRNA-mediated silencing of Erg. Relative Erg mRNA expression is shown (left). Cell numbers of Trib1 null, Trib1 hi, and Trib1 hi introduced with 2 different shRNA lentivirus are shown on the right. (D) Erg knockout by CRISPR/Cas9 in Trib1 hi cells. Cell numbers of Trib1 null, Trib1 hi, and Trib1 hi cells with sgRNA-mediated Erg knockout (right). (E) A Kaplan-Meier survival curve for Trib1 hi, Trib1 hi cells with sgRNA-mediated Erg knockout, and Trib1 null cells with Erg overexpression. Significance between Trib1 hi and Trib1/Erg knockout, and between Trib1 hi and Trib1 null/Erg overexpression was examined by a log-rank test. ***P < .001.