CDKN1A and non-small cell lung carcinoma: While many proteins relevant to NSCLC (e.g., KRT5/6/7, NAPSA, EPCAM, EGFR) were identified with both the label-free and equal loading TMT approach, many additional markers such as tumor protein p63, another SCC marker (TP63), NKX2-1, NRF2, KEAP1, and CDKN1A (p21), the cyclin-dependent kinase (CDK) inhibitor, which is also involved in both the KEAP1-NRF2 pathway and PI3K-AKT pathway32,33 were only identified in the TMT dataset (Fig. 2b).