DNAJB1-PRKACA is necessary for FLC growth in vivo in a slow growing PDX model. A, Tumor volume over time of a slow growing PDX (PDXB) transduced with inducible Ctrl shRNA or Chimera targeting shRNA, ± addition of doxycycline (Dox) feed. N = 3 for all groups. Linear mixed-effects model with cube root tumor volume was used to analyze data across the study duration. Group: P = 0.0423; Day: < 0.0001; Group*Day: < 0.0001. Only significant post hoc pairwise comparisons of growth trajectories at Bonferroni-adjusted alpha level < 0.0083 (0.05/6) are indicated. Inset is higher resolution graph of P+Dox group. B, Weight of tumor-bearing mice over time. C, Images of extracted PDX transduced with Ctrl shRNA or Chimera targeting shRNA, ± Dox feed. D, Western blot analysis of PDX from A and C, showing loss of Chimera knockdown in the P+Dox group together. E, qPCR of the TetR gene normalized to actin in tumors of Ctr− and + Dox at the end of the study. Two-tailed t test P = 0.0225. F, qPCR of the TetR gene normalized to actin in tumors of P− and P+ Dox at the end of the study. Two-tailed t test P = 0.0491.