TRAC and cancer: growth‐proliferation cell cycle‐associated genes such as Myc and Notch1,110 cancer‐associated genes such as Cdkn2a and Alpl, absence of TCR genes such as Trac and Trbc1/2 (Figure 4B) and elevated RPG expression, a distinct subset of precancerous T cells emerged (Figures 4B–F and S13A–D).