S100A1 and cancer: To determine the role of S100A1 in vivo, we inoculated LLC cells transfected with the S100a1 shRNAs (S100a1KD) or the scramble control subcutaneously into NOD-Prkdcem26Cd52Il2rgem26Cd22/NjuCrl (NCG) triple-immunodeficient mice and observed no significant differences (Fig. 2a), indicating that S100A1 was not essential for cancer cell-intrinsic fitness.