ACTA1 and neoplasm: Staining of B16F10 and MH6419 (both subcutaneous and orthotopic models) tumours for αSMA revealed that αSMA expression was primarily restricted in the perivascular area and showed dramatic reductions in tumours grown in Atf4Δ/Δ mice compared with levels observed in Atf4WT/WT mice (Fig. 3c,d and Extended Data Fig. 5a–f).