ACTL6A and esophageal squamous cell carcinoma: Recent evidence suggests that SOX2 and ACTL6A/p63 may regulate Hippo pathway components in osteosarcoma and HNSCC, respectively.14, 23 In this report, we show that SOX2, ACTL6A, and TP63 are co‐amplified and upregulated in ESCC samples.