RPS6KA1 and neoplasm: However, when LL97A lung fibroblasts were co-cultured indirectly with A549 or H460 tumor cells, anti-GPC1 mAb significantly decreased the phosphorylation of Src at Tyr416 and Akt at Ser473 and the β-catenin protein expression level in LL97A fibroblasts (Figure 6B and 6C), and the expression of phospho-MEK (Ser217/221) and phospho-RSK (Ser380) in co-cultured A549 cells (Figure 6D).