PELP1 and cancer: Two important genes found in the CTCs and primary and progressive tumors: LZTR1 (a frameshift deletion at p.T7fs) of the Wnt pathway and a transcription factor gene PELP1 of the estrogen receptor (ER) signaling pathway, which both closely relate to cancer metastasis reported in LCs (Słowikowski et al., 2015; Motta et al., 2019; Wang and Bao, 2020).