ACTA1 and cancer: In addition, expression of α-smooth muscle actin (α-SMA, Fig. 2, right panel) was detected within the cancer cell mass (GXC-001, GCX-004, and GCX-0018, green arrows) or/and in the stroma (GCX-004, GCX-016, and GCX-022 tumors, red arrows) of tumors, indicating the presence of cancer-activated fibroblasts.