PIK3CA and neoplasm: Co-occurence of truncal chromosome 3p and 3q loss/LOH, possibly a truncal loss of whole chromosome 3, was enriched in predominantly low/mid-grade tumours, suggesting as an evolutionary constraint associated with low/mid-grade patterns, whilst truncal chromosome arm 3q gain, especially truncal gain of focal 3q (3q21.3-3q29) encompassing several driver genes (TERC, 3q26.2; PIK3CA, 3q26.32) and tissue development- and differentiation-related genes (SOX2, 3q26.33; TP63, 3q28), as well as truncal SMARCA4 alterations were associated with purely solid tumours.