PIK3CA and colorectal carcinoma: Among soluble factors potentially involved in the fibroblast-CM induced PI3K pathway stimulation in PTEN-competent CRC cells, IL-8, IL-6, and MCP-1 were the most prominently produced by all three normal fibroblast cell lines tested (HFF, BJ, and NF; Supplementary Figure S5D); however, exogenous addition of recombinant IL-8, IL-6, or MCP-1 (alone or in combination) was not able to induce p70S6K1 phosphorylation at Thr 389, despite upregulation of p-PTEN Ser 380/382/383 levels (Supplementary Figure S5E).